The first issue to address is 'when'.
I don't think there is a 'magic' number here - and for well bred dogs with lots of drive, it really won't matter. We always wait till circumstances are such that I can really focus on the puppies - not when I I'm focused on getting a race team ready.
Always over 6 months, but may be 8 or 10 or more.
I don't do much 'prep work' with them. Again, with well bred dogs with lots of drive, I just don't think it is necessary. I do make sure the dogs are well leash and/or chain broke though - they NEED to understand how to 'give' to resistance. It is not fair to your team nor your pup to have it have to figure that out in a team situation - plus you stand a very good chance of ruining you pup permanently if he fights the pressure and 'wins'.
Our pups also have the advantage of having watched many hookups prior to their first time. I have heard it said that a young dog will learn from watching others, I don't know that I buy that - but what I do believe is that the pup gets familiar with the sounds and energy coming off the other dogs and that helps them take 'hook up day' in stride.
With a rescue dog and/or a non traditional sledding breed, you may want to start younger and put more ground work in.
Opie is right about 9 months old.
With puppies first runs you always want to set them up for success, so picking your team carefully is very important. I do the following....
1) Pick a SOLID front end. This is not the time to be dealing with inexperienced or unreliable leaders. Pick the best you have!
I chose See and Opie's mom Kelly for the task
2) Put a number of dogs in front of the pup with good drive. You want dogs that will keep moving even if there is back pressure from the pup pulling back. If the young dog happens to try to test to see if he has to go forward and is sucessful in stopping the team you have created a HUGE future problem.
I had Ditto, Google, Turtle and Scud directly in front. Lotsa drive!
3) Pick a running mate that has good energy and that the pup knows. I want a good driving dog, but not a 'crazy to go' dog nor one that will take unreasonable offense if the pup bumps into them.
For Opie I choose Ryka. They are kenneled next to each other and LOVE each other. Her energy is perfect!
Team sorted, you want to pick a relatively easy trail. I don't want to have to stop unless I want to on a puppy run. This is not a time to go exploring.
I hook my puppy up very last and then don't dilly dally once they are in the team. Move calmly but with purpose. Rushing and running around will add more stress to the occasion.
And now the key to it all GO SLOW!!! I cannot stress this enough. There is NOTHING to be gained and MUCH to be lost by charging down the trail at breakneck speed.
Scare a pup now and you will have a big, if not impossible, problem to overcome in the future. You will not harm your team nor your puppy by riding the brake. Quite the opposite actually.
SPEED RUINS YOUNG DOGS.
Most pups will figure it all out very soon but some will not. Just go as slow as you can but keep moving forward. Having someone run alongside the pup coaxing it can sometimes help a reluctant young dog.
I had one dog once that was quite reluctant to go and my handler, Katherine actually took a few steps alongside her while holding her up by her harness. Worked like a charm and she was off and running on her own in just a few steps. That dog, See, was leading the team today.
I don't fret over what side of the gangline they run on and will slow down but let them sort out any minor tangles they get in on their own. Stopping every time they get even slightly tangled will teach them 'learned helplessness'.
No need to chatter at them nor stop and bother them - they have enough to sort out right now. The reward of actually running will be more than enough anyway.
A quarter mile into our run (sorry - messed up the clip of leaving the yard)
A mile and a half or so into the run
Sorry, messed up the finishing the run video - but here is a still
You can see he is on his own side and into his harness much better. The MOMENT his tug starts going slack I will slow the team down to the point that he gets back into his harness again.
I do not believe in teaching puppies that it is okay to run with a loose tug line - nor do I ever undo the tugline and let them run without pulling. They need to learn that keeping the line tight is their job - and how to use the pressure from the tug line to help balance.
Don't run the pup too long. Always leave them wanting more!
Remember all puppies, even littermates, are different and will progress on their own schedule. Don't be in a hurry.
Give them time to sort everything out and move forward with confidence! It will pay off in the long run!!!