MHMama,
Can't beat a $2.59 for a good behavior book.
If your interesting in Dog Behavior,
The Dog's Mind by Bruce Fogle DVM is a excellent book.
I just bought "On Talking Terms with Dogs: Calming Signals by Turid Rugaas.
It's a VERY thin paper back-book for $9.99, but it explains canine language along with how to understand it and also
use it.
A couple of my friends who are
into behavior/training recommend,
The Dog listener, by Jan Fennell, but I have not read it.