great question! There's a list called Start Puppy Training that you can join that will help you a lot. There are tons of great trainers on that list and they'll answer any question. That group is here:
http://pets.groups.yahoo.com/group/spt/
I'd also recommend a few other sites,
http://www.clickertraining.com/
and a blog:
http://www.clickersolutions.com/blog/blog10.htm
I have been playing the 'rule outs' game with my pup a lot. This game is also called "It's your choice" and was named that by the folks up at Say Yes. The basic explanation is that you want your dog to be able to recall to you no matter what the distraction, at first. In agility, we escalate the game to the point that we can scatter liver treats amongst an agility course and have the dog perform the course as well as if the treats were not there. But the point of this is that your dog knows that he is not to take the reinforcer, no matter what it is, until you release him to do so. Ideally you start with your dog in his crate - and the dog is released by you ("OK!" or "Break!" etc; train this separately if your dog doesn't know this game) So, the pup is in his crate. Scatter some low-value treat around (for my dog, this would be carrot slices and broccoli - for yours, it might be something else) and have high value, stinky treats in your hand. Your dog will hopefully smell these, but don't show him these treats or lure him with them. Give your dog his release word, and call him to you. Be ready - he may stop to investigate the treats. If he does, gently nab him and put back in crate. Try again - it may take more than twice for him to get it. Reward heavily and with much excitement when he comes straight to you!
It's pretty easy to increase the difficulty of this game, which you would do by placing higher value treats to tempt him - also, being farther away from your dog (be sure he won't stop to self-reinforce on his way to you!) If your dog is toy-crazy, place a toy down there too. Be sure to be fair to your dog and increase the temptations slowly. If the dog fails 2 or 3x, he is telling you that you're moving too fast - back up to an easier setup.