Hi! I regularly jump 3 x per week, at least. Michael Olijade's tapes are great for teaching different steps which you can use on your own to your own music. I started by doing 1 minute jumping than 1 minute toe taps and built from there. Now I do 30-45 minutes straight. Learn how to do the boxer shuffle. You are still working but that move is a resting move in a way because it takes pressure off of my calves. I do 1-5 minutes of a particular jump (basic, side to side ski hops, Ali shuffle, aerorun, etc.) and then do a couple of minutes of shuffles. I've been at it about 6 years and still love it.
I love Micheal's original Aerojump the best, but his 3 dvd set is good also. I haven't mastered the moves on the advanced one, but it is fun to try. Just train your kids to stay out of the way (a rope in the face sucks) and wear long pants to begin with because you'll probably get smacked every once in awhile until you get the hang of it. I also jump on puzzle mats from Home Depot to help absorb shock, but I have never had any pain except in the calves (burning!) or if I hit myself with the rope.