Katie at runsforcookies.com who started at 253lbs. and now weighs 134lbs. gives advice on how to become a runner. She says that she is in no way qualified to give advice to runners. I think her success as a runner says she is. She is also a good writer, so check out her website.
Her advice distilled:
1) Sign up for a race..yes you read that right, just pick a race a few months down the road.
2) Start running three times a week. Start by running and when you can’t anymore just walk.
3) Run slowly, there is no reason to run fast when you start. As you get in better shape the speed will come.
4) When you feel you are ready, try this: if you are running three times a week, break up your runs into an easy run, a speed workout, and a long run every week.
5) Stay consistent! If you fall off the wagon it is very hard to get back into the running routine again. Commit to running three times a week and don’t skip a run unless you absolutely have to.
Check out the full article –> How to get started as a runner