How Early is Too Early to Train?

There has been a lot of debate about how early is too early to train your hunting dog. I'm getting my puppy soon, and I'm thinking that I want to start with some basic commands immediately. But are there certain things that are worth waiting for?

I'm basically thinking that commands that work well for both a family dog and a hunting dog should be the first ones taught: sit, stay, heal, come, etc.

Famed gun dog training author, Richard Wolters, believes that you should start as early as 7 weeks (Boru will be 7 weeks old next week!), while many other authorities think you should wait until the dog is a year old.

Personally, I'm leaning toward getting my dog whistle and field ready as soon as possible. I hope that he's in a duck blind with my by the time he's a year old.

So, how early is too early? When should I break out the frozen mallard wing to teach Boru the joys of retrieving a downed duck?