Couch to 5K. There are many different sites that show the workout and training plan, but this is the one that I am using. If you have an iPhone there is even an app for it!
I also joined the website Daily Mile to use for tracking my workouts and keep in touch with others doing the same. I think that it is really great for getting encouragement from others trying to get in or keep in shape.
So, if everything works out right, in 12 weeks (or less) I should be able to run 30 minutes straight, with no walking, and run at least 3 miles in that time...I hope to be able to do it!
And hopefully in 12 weeks I can finish a 5k and you can sure as heck bet that I will be as happy as this girl when I complete my goal!