Stay far, far away from Wolters (water dog/game dog). His methods are outdated and to begin with were ineffective and sloppy at best. I also advise not reading either of Milners books because they're illogical and not very well put together.

A great all around book for retriever training is the 10 Minute Retriever by John and Amy Dahl. http://www.amazon.com/exec/obidos/tg/det...ce&n=507846

Also, books by Lardy and Tarrent are very good tools.

Retriever training generally starts at 7 weeks of age, so nope, she's not too young. Read all you can on it and ask questions. The library is a great resource for books and videos.