Many people have written books on bird dog training, some better than others. We are still learning but here are some of our favorites:
Point! Training The All-Seasons Birddog by James Spencer
The Training and Care of the Versatile Hunting Dog by Sigbot Winterhelt and Edward D. Bailey - also known as the NAVHDA Green Book
Best Way to Train Your Gun Dog: The Delmar Smith Method by Bill Tarrant