The above information/links far surpass my knowledge on the subject, but I can pass on a couple of tips that have helped me.

1. Don't underestimate the "field trips" as mentioned above. You need to give your pup unlimited amounts of what Bill Tarrant called "puppy timing". Let him explore different covers/scents/etc. in a totally carefree situation. It will do wonders for development of natural hunting instincts later.

2. Don't expect too much too soon. Dogs will do great things with lots of field experience combined with proper and gentle training.

3. For a retriever, obedience (esp. "stay") is paramount.

4. If you want a dog for retrieving waterfowl and chasing pheasant, work on solidifying the retrieving skills first. Basically the dog will use polar opposite skills for ducks/upland. If he has the upland skills first, it may be very difficult to break those habits and get him to hold steady for waterfowl.

Good luck . It will be fun regardless!