Hi Dave--my dh has looked at p90x and I've heard good things about it, but we haven't tried it. If you don't get any responses on this side, maybe post on the events side of the WISH boards and see if anyone has done it.
I started off in January almost exclusively on the elliptical. My exercise goal for January was 720 min and I hit 1166. In February I added in strength classes--most weeks twice a week. It was brutal at first, especially on my knees, but as I lost more weight it got easier. I started adding a little more treadmill in during Feb. and March.
My DH ran a 1/2 in April and all spring kept saying that we should run together--I used to run (in my younger days

) but never made it past 5 miles due to injuries. So I humored him.

I really didn't think it would last long. We ran together all summer and I have run a couple of 5ks, a 10k and 2 half marathons. My next half is at the end of February.
Currently I am working out on average 5 or 6 days a week. Usually 3 runs, and two strengths and a couple of crosstraining days--I double up a lot on strength days. I think whatever you end up doing, a combination of strength and cardio is the key. And listen to your body. If something hurts, stop. Get good shoes, and make sure you are eating to fuel your body. My DS is 19 and can get away with sporadic exercise and eating what he wants. I can't. And as my workouts get longer and longer I really know it when I am not eating well.
Start slow, and hopefully a year from now you will be posting on someone's thread about what worked for you in the new year.
