hockey,
Good! Then I really urge you to first start with your lab. Even more important than training your dog, is training *yourself* to be a good trainer, as well as handler. I encourage you to also at least begin trialing with your lab before getting your new puppy. Though the trainign might seem to be over once you reach competition ready, it has just begun because there's always so much more to learn. But don't worry, this is what makes it FUN, even years and years after you have begun.
All the while that you are training your lab and gaining experience, I encourage you to be researching the Aussie breed very thoroughly, talking to breeders, etc etc etc. No such thing as being TOO prepared for a new dog!