Hey STN!
I think the easiest way for me to do this is start with the end and then we can work our way to that. A while ago, my brother and I started putting together a dream itinerary for a trip around South America. A week ago I showed it to my parents, and they said if I included them, they'd put in as much time, money and effort as it took to convince me to take them along.
I've never ridden a motorcycle before, and as far as I know neither have they. I've done some cycling tours, and I've seen plenty of families touring around the Beartooth pass and such. And I've read Zen and the Art of Motorcycle Maintenance. That's about the extent of it. But all of those things convinced me that seeing South America from the seat of a bike would be much more memorable than crammed in a compact car or stuck in a variety of bus seats.
Since I'm assuming you can't (shouldn't!) show up at the rental office in Puntas Arenas with no hours on a motorcycle and expect to be able to rent two (four?) bikes, I figure I should have a plan of action to prepare us for it. So far these are the steps I've come up with:
1. Take a motorcycle safety class. That's about the most important thing I think I've gleaned from the forums so far.
2. Buy a used bike as close as possible to the ones we'd be renting in S.A. Ride it every weekend/as much as possible in the summer with my brother. Learn what makes it tick, fix what breaks and keep it running smoothly.
3. Buy a bike from parts and make my brother and motocross buddies help me bring it to a working condition.
4. Drive both bikes cross-country to my parents for a longer practice tour during the summer. Leave one with them to practice their riding and touring skills.
5. ???
6. PROFIT!!!

7. Go to South America.
I have many many questions, but don't worry, I'll troll the forums before I ask all of them. So the main ones are:
Are any of these steps in the right direction / Should I be taking a different tack?
How long should I expect the preparation/learning/practice process to take? Am I too optimistic to think this can all happen by winter 2014? 2015? 2020? Nuclear winter of 2058?
Thanks in advance for any direction and advice!
DaneBramage
edited for a better attention-grabbing name.