Depends on rather the topic - but one I'd certainly recommend is "Before You Get Your Puppy" by Dr Ian Dunbar. "After You Get Your Puppy" is very much worth your while also. The first, however, can be obtained for free
It is downloadable from here (right hand side of page): http://www.openpaw.org/about/board.html
Anything else you can find by that author (he's a canine behavioural specialist) is worth grabbing.
Other than that, you might find some of these training/behavioural books very useful:
"The Dog Listener" by Jan Fennell
"The Culture Clash" by Jean Donaldson
"The Other End of the Leash" by Patricia McConnell
"Don't Shoot the Dog" by Karen Pryor
"How to Be the Leader of the Pack" by Patricia McConnell
Plus, Dr Pitcairn's Guide to Natural Health for Dogs and Cats.