Rather than use standard bookcases, which can be a pill to get around corners, you may need to use a modular system that can be carried in in pieces and adapted to the shape of the room.

How is the temperature and humidity in this room? Cool and dry enough for books?

What are the dimensions of the room? From the photo it looks like you could single load the shelving (put it only on one wall).

If you do make it into a library, I think it's screaming for cork flooring. We have cork engineered floors in our kitchen (5 years old now) and it's not very expensive, at least for the more neutral patterns.

Perhaps instead of bookcases, you need to do shelves directly on the wall. That'd save you any space lost with the back thickness of the bookshelves and the fact that you'd have to push them against the base molding or remove it.

Can you tell us how wide that space actually is? There isn't anything to give us scale in the picture except for the width of the handrail.

One more thought - the wall on the left is an interior wall, am I correct? If you are lucky and it doesn't contain ductwork, you could pull off the drywall and recess your shelves into that space - it'd gain you another 3-5 inches or so. Paint or stain the studs to match and it could look really nice.

I also think that, if you aren't too desperate to use every inch of the space, that back L region looks like a fantastic place for an easy chair. You'd have the light from the window during the day and it could be really pleasant unless you're in an area where it gets just too hot.

@Fisheggs, I suspect that interior wall is shared with an upstairs bedroom or bathroom. I don't recommend making shelves out of wood studs unless you have nothing else going on next door. You have accoustic issues, you have conduit issues, cleanliness issues... keep your walls enclosed.

Btw, this is a nice MidCentury Modern house with potential. The architect in me wants to rip out that attic floor to open up the stair well and house entrance below. Put in some nice wood open riser stairs and cascade daylight to the first floor below.

I apologize, I thought this was Dwell Magazine for a moment. :)

I don't know if you're a parent or not, but that's a little kid's dream playroom!

When I saw the picture, my first thought was "reading nook!" so I'm glad you're going that route, or want to. I would build in shelves; it's much, much easier than dragging full bookcases upstairs. Maybe make them deeper on the bottom for hardbacks and narrower on top for paperbacks? It would make the space seem larger, perhaps.

@medusa12120, I'm a professional librarian and also have a CARPETED library in my own home. The public library where I work is carpeted. Why would you imagine that carpeting is harmful to books? I have never heard or imagined that.

Danielle, in our previous house, we had shelves lining an upstairs hallway. In our case, the illusion of space was enhanced because the other "wall" of that hall was an open stairwell with only a rail so the visual space was essentially doubled. In your room, I would definitely only put shelves along one wall and make sure the other wall is light colored. Maybe even use metallic paint or wallpaper so there is a slight shimmer of reflection, to make the area feel less closed in. (But there should be enough space to walk by and see the books.)

Depending on your budget, you could do wall mounted board-and-bracket shelves (cheap, effective, not so attractive.) Or you could do IKEA Billy shelving -- they have an app for space planning so you can get what will really fit. These could be built in the space, saving the problem of getting pre-made shelves up the stairs. Or you could buy pre-made and hope for the best. (Be sure to shim them tight to the wall.) Or if you have some cash, you could have custom built-ins made. This would be the most elegant, but probably the most expensive (unless you are handy or have handy friends/relatives to get to help.)

In any case, I'd spend the money to have an electrician install power outlets up there (as well as lighting.) MUCH easier to do before loaded shelving appears and you see the necessity! (As project manager of a $200,000 renovation of the adult floor of my library, as me how I know!!) (OK, it's actually not my fault, I DID see the need but the Trustees vetoed the expense -- so now the Teen area can't plug anything in such as the electronic photo frame they want to use instead of paper posters...)

If the L shape doesn't go very far back, you might want to door that end off for actual attic storage and just have the straight hall for books. Put your reading chair in the corner by the window and move it out of the way to get into the closet as needed. (Might be a place for holiday decorations, etc.

Oh, one other issue -- make sure the space is properly insulated. Storage spaces often are not. And attics are tricky because you need air flow from soffit and ridge vents (in the north) to avoid ice damming in winter, and to maintain proper interior temperatures year round.

No outlets? You need lots of light in there.

A 8 inch deep bookcase is plenty deep for the majority of books an English professor reads and I don't think that would intrude much into the room. Also, if you choose half height or even 3/4 height bookcases along the window wall it will feel less crowded than full height cases. You could put some deeper, full height cases along the other part of the L, for any bigger sized books.

Or, if the foot of the L is pretty shallow ( I can't tell from the picture), you could make it into a fantastic built in nook, with a really cushy mattress-y seat and lots of cushions. And just put some deep shelving underneath the seat, for the books that don't fit in narrow shelving.

1) Assess your book collection to see if you can put all the smallest books in this library: the small chapbook size and the industry softcover ones. Then plan another spot in the house for the largest books.
2) Assess how many thin-spined oversized books you have. Can you devote a portion of the space to shelving that holds books face-front? Like this:http://bit.ly/LWmyO7
3) Duane Hill's idea, the ideas about building shelves between the studs, and the issue of the weight of the books suggest that you should spend a little money on hiring an engineer or contractor who can assess the structure of the house before you proceed with design ideas.
4) I love Duane Hill's idea combined with some of the wonderful staircase libraries that Apartment Therapy has documented: http://bit.ly/LPQfKB
PLEASE post an After pic!!!

I would love to see floor to ceiling books in this space, without the visual divide of shelves. The idea of just stacking them is very problematic, so what about making shelves and covering the shelves with old book covers? (like make a trip to a used book store and buy stacks and stacks of dollar bin books). You could gut the books and glue them around the shelf.You could even get Ikea Billy Bookcases and assemble them in the space, make them look built in, and then cover the shelves in book covers. OR just do invisible bookshelves like these: http://pinterest.com/pin/67905906851488983/ or http://pinterest.com/pin/149252175120916083/ Cheers and good luck! :)

I would go put up Elfa solid shelving from the Container Store. Come in lots of depths and you can custom plan them. Plus, crazy easy to install.

If it's as narrow as it looks, I'd put twin mattresses in an "L," add lots of pillows and make a Moroccan-style lounge. You can store books downstairs and just bring up a few that you're reading.

I have a friend who couldn't find bookshelves that are long/big enough. So they ended up using reclaimed wooden planks to build their own wall bookshelve. you may want to paint the planks white in your case to make the space look bigger but otherwise, that may be an option.

I can't really tell what's going on from the photo. Is that a rail? Are there stairs there?
And is there a light fixture on the ceiling.
I think a library is a great idea. The corner by the window would make a great reading nook.
You could replace the fixture with an overhead reading lamp.
Consider hiring a carpenter to make built in shelves. Maybe with a window seat.

I'm wondering, first, how many books you are thinking of putting up there. You say "a little library" but then mention you're an English prof, so your idea of "little" might be quite large :)
Also, how wide is it? Looks like perhaps four feet?

You might want to get a contractor in to check the weight capacity of the floors and walls. Also, if your contractor has an electricians' license he might be able to tell pretty easily if it would be difficult to at least provide the area with a grounded outlet or two.

If that L bend is a good size for it (hard to tell how far it goes) *and* you can get some sort of light source back there, that would be a cozy little area for a nice chair and perhaps a small table.

If your contractor indicates that the floors and walls are sturdy enough, you could easily build shelves intended to hold books at an angle (or small knickknacks, whatever).

I helped a friend build a 'library' in a closet a couple of years ago out of relatively cheap lumber which we then stained and painted to look like hardwood. (And because I'm a book geek, we lined them with acid free board to buffer her books from acids in the wood.)

Basically, we built shelving using exclusively 1x6 lumber and since we were doing it ourselves we could choose our own shelf heights: 16 inches headroom (tall enough for folio sized books) for the bottom shelves, then a 10 inch shelf (standard hardcovers), then 8 inch shelves up from there (fits most paperbacks).
*When I say headroom I'm referring to the space from the top edge the books are sitting on, to the bottom edge of the next shelf up.

For your low-ceilinged space it would be a matter of aesthetics versus feet of shelving. For the 6ft area I would (from bottom to top) simply go with 16-10-8in shelves and use the 38-inch height top as display area. that would be barely above the half-height point on the wall.

I know, you're going, I DO have 12x15 folios, how do I get them to stay on the shelf? very simply, you angle the books on the shelf (like magazines at the store). It takes up a lot less lateral wallspace. at absolutely worst, you lose perhaps one linear foot of shelving per case this way for the widest books. Hardcovers hardly have to be angled at all: you lose maybe one or two books' worth of space. Paperbacks will fit spine out, completely straight.
And of course if you are extravagant and make your sheves 8 (!) inches wide, the angle the books are kept at can be much less shallow and hold even more.

Other thoughts:
If you do decide to build your own shelving, you might consider leaving the upper part of the walls open so the place doesn't seem like a cave falling in, or leave at least some blank restful areas open. At most I think I'd go with four shelves, 16-10-8-8, which bookcase would have a total height of 47 inches (assuming your bottom shelf is flat on the floor).

I might (if time and $ permit) put in a couple MORE round windows (they are cool!) spaced along the long bar of the L.
If not, no big deal, but I definitely would place mirrors opposite the existing window, where ever light strikes, to bring natural light into the area (again, avoiding the caving-in cave feeling).

However, as someone pointed out, you do want to try to avoid inadvertantly destroying your books. If they're not particularly valuable, don't worry too much, but if any are expensive or rare, you won't want to store them in a former attic unless you've made sure it's a book-healthy environment. Really, rare books should be kept in climate controlled environments, but even I don't go to that much trouble except for four VERY old books I own.

Basically, if the air in your L is too dry, the bindings and papers will deteriorate; if it's too damp you risk introducing mold or pests. Direct light (natural and most types of incandescent) will photodeteriorate your bindings/papers/colors on the exposed areas of the books, (that's how the edges get all yellowed and crumbly, which can happen very quickly). However, you can get various treatments for window glass to cut down the amount of UV radiation getting in, and then there are of course always blinds or shades. Or simply fashion doors or covers for your shelves.

And remember YOU have to be comfortable here. Does it get really hot in the summer? Cold in the winter? You might have to check if this area and its roof are insulated well enough for YOU to be happy there!

If you go with half-height shelves, I'd put not only a mirror or two on the walls but also some nice bright prints or paintings. Or even frame the jackets of favorite books as decoration :)

I know this was loooong, but I hope it helps you figure out what to do with your interesting space! Good luck with your project, and congrats on the new house!