I agree with everyone else, let em be puppies. If you want to do anything to help em out in the long run tote em around the neighborhood on your 4wheeler from an early age to get em used to riding, I did this with the last set of pups I raised and it helped out alot. by the time they were ready to go to the woods they were already used to the 4wheeler. Another thing you can start doing now is jusut tote em to the woods and walk around with em, let em explore and range out a bit, even at such an early age it will help give you an idea of which ones naturally use their nose and range out.
nail on the head there Justin!
You can let them be puppies at the same time of judging them and see what their natural abilities are. Like Justin said, and IMO, I think the best thing for puppies is to tote them around in the truck getting used to the box and all the sounds, let them walk with you through the woods to start getting used to tall brush and thorns and such. If you have a pen with hogs in it let them see it, and start hearing the other dogs baying the hogs, or barking at them. The dogs will show you when they are ready, and you will see it in their body language. Hope it helps and good luck.