My very very favorite competition obedience book is by Judy Byron and Adele Yunck. I believe it is called something like Competition Obedience: A Balancing Act or something like that (it is sitting upstairs right now). It is very comprehensive and thorough. It takes each exercise and describes the foundation work and vocabulary you need to develop for that exercise, then takes you through the steps of teaching it, from beginning to proofing. (Adele Yunck has written a separate book on proofing. Sadly, Judy Byron died in the late phases of the Balancing Act book.)
It is always a good idea to take classes and attend seminars when you can. But if any book could take you from Novice A through Utility without ever taking a class, it would be this one.
A great website for dog books is
Welcome to Dogwise.com - Dog Books. It is much easier to find books for specific performance events and issues there than on Amazon.
I belong to two Yahoo groups--one is an all-breed competition obedience (
dogobedience : For people who are competing or training), the other is a poodle obedience group (
ObedPoodle : ObedPoodle). Both groups are very helpful and friendly, but of course my heart is with the poodle group.

There is a lot of friendly chit-chatand brags on both lists, but if you ask a specific training question, you will get lots of good help. There are some truly awesome trainers on the poodle list.