
As the daughter of a librarian who used to run around the closed library on the weekend with her sisters, I can attest that playing librarian is really fun and I would have loved this Little Librarian set to have at home. Their motto is "Be a librarian. Just add books!"
The set contains library cards, overdue slips, book pockets and cards, file folders, reading awards, bookmarks and a reading journal. It's a nice way to learn how a library works, but mostly it's a fun way to enjoy imagination-driven pretend play.
Little Librarian was created by mother and daughter Mandy and Kris Miller. Like many young children, Mandy loved the library and loved playing librarian. Mandy and Kris have some great ideas for how your children might "play librarian" including having a story hour at your pretend library and hosting a book club. Recruit siblings, friends, neighbors, aunts, uncles, pets and stuffed animals as library patrons.
The Little Librarian Kit ($19.95) is sold online through several sites as well as through Amazon.

Ercol Bar Stool
As a mom and a current library student (and hopefully future librarian), I love it! I would have enjoyed this kit when I was a kid. Seems like something that would be fairly easy to DIY, too.
I am so loving all the book posts over here!!! Awesome!!! We organized our books like a library with book cards and book bags just to curb the book chaos around our home!!!
http://www.se7en.org.za/2010/04/06/saturday-spot-the-book-nook-updated
Sorry folks, that was the wrong link - please forgive me. I wish I knew how to delete a comment. This is the library link I meant to post, with book cards and book bags: http://www.se7en.org.za/2009/02/22/the-book-nook-revisited-in-se7en-steps
As a future librarian (and current library employee)... WIN!!!! I'm totally buying this for my future children!
And then after you're done playing with these (which are totally cute, by the way...) have them learn more about real-life librarianship by getting on a computer and doing database searches! ;-)