I have to agree with Scott, that is by far the best animation book I own.
I believe i have in a pdf format on my computer so if you want i could send it to you :)
The Animators Survival Kit is worth getting as a book, instead of pdf. It's priceless reference to have when you plan walk cycles, for example.
I agree,I got it as a pdf and printed it out,it was a much cheaper option for me :)
Animators Survival Kit by Richard Williams is great for technical stuff!
I would also consider Character Animation Crash Course by Eric Goldberg, it doesn't replace Richard Williams's book, but I feel it's a great add on specially on acting topics.
And if you have a bit of extra bucks consider getting a Muybridge book, to have some stock on reference :)
My book! (Maybe a little basic, but a good beginners guide...)
looks very good for beginners..i'm also in a get-some-books-phase and will consider yours into my collection
Animator's Survival Kit
The Illusion of Life
Timing for Animation
These are three "must-haves" for any animator working in any medium. Although they are addressing hand-drawn animation, the information in them applies to any medium, including stop motion.
I have a bunch more, but if you master the information in these three I would put my money on you becoming a top-notch animator without any other reading.
The next book, or rather books I would recommend after these three would have to be the Muybridge books on human and animals in motion. The first photographs showing stopped motion of humans and animals, and still the best, they will give you a great reference from which to work and extrapolate.
Books & videos I recommend to my animation students.