Karen Berger's Backpacking and Hiking book is really easy to read and has nice illustrations. It covers the basics for beginners.

Ray Jardine's book may be a good second book to read as it gets much more advanced. It's more oriented towards a long distance hiker, but there's still a lot that you can apply to shorter hikes. He may be a little irritating to read...he comes off as a bit of a pompous hippie to me, and I've heard from other that that's the way he actually is, but don't let that stop you from getting what you can out of his book.

I've heard Complete Walker is good, but I haven't read it yet.

There's also a For Dummies book that appears to be pretty comprehensive, but I haven't read it yet.

The last two books are on my reading list. Even though a lot of the basic stuff is old knowledge, it sure doesn't hurt to review.