It is difficult to know how to integrate things without knowing what you need in your new apartment, but you could sell these things to students that live in your former dorm.

Having been in the same situation not too long ago, most of these things should be easily reusable in your new place, you just have to think of them differently! I'd keep the comforter for overnight guests, and the sheets can either be cut and sewn into curtains or folded and sewn into a laundry or storage bag, depending on the pattern for the curtain option of course (and your new place's color scheme.) If you have a space for the mini-fridge, you can always repurpose it as a wine fridge or other cold drink storage. Definitely keep the mirrors, especially if one is full length- you never know where you'll need that! Mirrors will also help to open up your new place if it feels small, and if they aren't too big you can use them on coffee or side tables as trays or for added interest (rather than hanging them.) And if all else fails, there's always Craigslist. :)

I had a similar problem recently and I used my full length mirror as a headboard. I just bought wall mounts and hung it horizontally at about eye level above my bed. I have a tiny bedroom and it really helped to open it up. I also painted the frame bright yellow so it wasn't so bland. I've gotten several compliments on it.

shower caddies are also useful as storage for cleaning products

save the mini fridge! worst case scenario, leave it unplugged and store books in it (little English major tip for ya there). It also makes a very college-esque end table- top it with a pretty vase or bowl of fruit and maybe a mini fabric runner and voila!

also, if you don't have space to store the extra bedding anymore, you might be able to donate it. I gave all of my twin xl stuff to a battered womens' shelter :)

I used to live in the dorms but am also moving into an apartment, so I'd say...

- keep the sheets. you can use them to make curtains (we did that this summer), as a picnic sheet, or to make up an air mattress for when you have guests
- use the minifridge as another fridge - for drinks or something.. especially if you're living with other people, the fridge will get full pretty quickly and you'll be thankful you have somewhere else to store drinks and things
- the shower caddy can hold pretty much whatever you want it to - pens, jewelry, hair accessories, make up - you can put it on your desk, in the bathroom, etc.
- the mirrors and extra lighting - depending on what it is, you can probably still integrate it into the apartment (that's what we did - we've got different people's lamps and chairs from when we were all in dorms), see what it's like once you've moved everything else in

worst case scenario, you donate it or sell it, but there's definitely a lot you can do