I have to say, in all three of these, of course, the "draw" is the people. I could care less about teaching a curriculum, even one based on the Bible without those little connections with my students.
In the library, getting to talk to the librarian and librarian assistant is often a high point in my week. Not only do I get to talk to them, but my #2s friends all work in there, so every time I volunteer, I get to see his friends. Strangely, my two middle-schoolers don't use the school library, so I never get to see them (maybe it is because I buy them too many of the books they want - yes, it is a almost a disease how many we buy). Anyway, I have gotten to know these friends better and have been encouraged by this interaction.
The librarian herself is funny, sweet, intelligent and loves books. What better friend for me than that! It also helps me to feel that on this somewhat difficult and hostile campus (especially for #2), I have allies. I have people there that know me and through me, know my kids. These two ladies have listened to me about a lot of stuff that has happened with my children. They have encouraged me and helped me in so many ways. The work itself, well, it is hard sometimes, taxing, tedious, but I feel like I have made progress when I leave. The shelves are straighter and more in order. And, I joke that I am "making friends" with the nonfiction - the most difficult area in the library. Not only that, but this little window is almost a workout in and of itself. I feel completely worn out when I leave. Just think, I am lifting weights, pulling and pushing weights, kneeling and standing over and over...you get the idea.
Of course, the reason I volunteer is to make the world a better place, hopefully, but I get so much out of it myself. I get uplifted, encouraged, and learn so much. I feel that one benefit of putting the children in school is that we are so much more integrated into the community and have met so many interesting people. I wouldn't take anything for the friends (and acquaintances) I have made through the school and community connections we have made.