I've trained Labs for over 20 years now and I'm getting better at it every time. I always refer to Wooter's books. "Gun Dog" and "Water Dog" are my favorites.
They are easy to understand and are basically a step by step guide. A good read. I like to start training my dogs at 7 weeks. This is mostly play training but it makes them want to learn throughout their entire life.
One thing I urge all dog owners to train their dog to do is sit on whistle command. Not only gun dogs, but all dogs. That little "trick" can keep your pet from getting hit by an auto or get into any other trouble. And a whistle carries alot farther than your voice.