I volunteer at our local library on Fridays.
I shelve books, I shift books, and I haul books around on a cart. It sounds boring, but it is really fun! I get to see all the new books before anyone else. I even find nifty things for the whole family to read. I usually volunteer after they've had Story Time because that's when they have the most books to put away. Story Time kids check out a lot of books. (I don't know why this is, but it is a universal phenonmenon.)
I used to work in a library, so I am quite a commodity. Basically, I know 3 things: I know my alphabet, I know how to count (that helps with the Dewey Decimal System), and I know the difference between fiction and non-fiction! This knowledge allows me to shelve books correctly. The fact that I shelve at lightspeed is a bonus. The staff often asks me how I shelve so quickly... that's easy -- I'm originally from New England and we New Englanders move fast! If you sit still for too long in New England, you'll freeze solid.
I enjoy volunteering at the library because the staff is friendly and appreciative. I enjoy the staff immensely. Librarians are a fun bunch, you know. So, if you need something to do, try volunteering at your local library. You'll be glad you did.