Marty, you might want to check out sites such as this: C25K for help. DD1, who never exercised until she turned 30, is using this pattern to get in shape. There are a variety sites that use the concept of going from the couch to a 5K race in six weeks. There are also podcasts you can put on your music player that announce the interval times so you don't have to keep looking at your watch. She laid that track over some music just to make it less boring.

Its working for her as she's now up to jogging 2.5 miles without stopping in just a couple of months after starting from zero.