Julie,
Far and away, the best "everything" cycling book, in my opinion, is "A Woman's Guide to Cycling," by Susan Weaver. The revised & updated edition came out in '98. I've read and re-read this book-for tips, basic understanding, wrenching advice, gearing advice, and general support & motivation. It's easy to read & understand, good illustrations. It's put out by 10 Speed Press, $16.95.
I have 3 other bicycling books, but this is my absolute favorite.
Enjoy!
MaryS