A journey of a thousand miles (or 26.2) starts with a single step and all that blah blah blah, but how does one actually prepare for a marathon? I looked online for some training programs and many of them started with Day 1: run 6 miles. Sorry, can't do that! So I had to come up with another plan.
I actually wasn't in terrible shape when I started. I finished the Belle Isle triathlon in June 2009, but I had focused on the bike and the swim and didn't start training the run component until six weeks ahead of time when I went too far too soon and got shin splints. I couldn't deal with that same pain during 11 months of training, so after spending the summer mostly biking and walking, I decided to start the marathon from absolute square one.
I looked online for a 5k training program and found the Couch to 5K Running Program. The plan was three days a week that should take 20-30 minutes. I can handle this! Even better, the author acknowledges that "It's easy to get impatient, and you may feel tempted to skip ahead in the program, but hold yourself back. Don't try to do more, even if you feel you can." Well I took this advice to heart and took my sweet time logging all the distances, even when I knew I was capable of doing more. If the program said to jog 60 seconds then walk 90 (repeat for a total of 20 minutes), that's exactly what I did and nothing more!
It took me 3 months to get through the program, which is designed as a 9-week program but it worked and I could successfully run a 5K for the first time in years.
I normally disdain using treadmills, but in this case, it was easier to monitor the times on the machine to nowhere.
The entire training program can be found at http://www.coolrunning.com/engine/2/2_3/181.shtml