S.R.
I started it, then fell off the wagon when I traveled over the holidays... lol.
The first week you alternate 60 seconds of jogging with 90 seconds of walking. That's it. The next week is alternating 90 seconds of jogging with 2 minutes of walking. I did just fine with it while I was doing it, and I hadn't actually exercised in a little over 2 years. Granted, I've played with my kids, but I hadn't actually worked out. I don't know if you've actually looked at the plan, but it's on their site on this page if you scroll down far enough. http://www.coolrunning.com/engine/2/2_3/181.shtml
It also says on the page that if it starts going too fast for you in the program, just stretch things out. Keep with a particular day's regimen for a couple of extra days if you need to. It really seems like it would work really well if followed through with!
As I said, I fell off the wagon. When I jumped back on, I didn't jump back onto the Couch to 5K wagon, I just jumped back on the jogging wagon and decided to use my inner recording of my husband for motivation... :) That and the fact that I wanted to trim an inch or so (or as much as I can!) before he comes home, which is SOON, YAY!!! This new wagon, I jumped in doing a 5 min warmup, 1.5 miles jogging, 5 min cool down. I know the Couch to 5K program doesn't list it, but it's ALWAYS a good idea to do a cool down walk just like you do a warmup walk. And also do POST exercise stretching as well as pre-stretching! I promise, you won't regret it!