Game Dog, by Richard Wolters
Gun dog training retrievers & spaniels, by Ken Roebuck
Retriever training: the complete guide to developing your hunting dog, by Tom Dokken
Training the Hunting Retriever: the new program, by Bill Tarrant.
The second and fouth book might be out of print, and you may have to looked for them in used book sources.
I used the first two to train my first dog (American water spaniel), and then I've trained two chessies since. Currently, I have a 6 month old female lab that I'm getting ready to do some outside work with as soon as the weather gets a little better.
Good luck......................