If you're looking on getting started with a 5K program, C25K is great. I haven't personally used it but I've read about the results from fellow bloggers. It's amazing what they can do if they keep pushing through.
I started off setting small goals for my running. Run for 3 minutes straight. Then 5. Then 10. My first mile time was 13 minutes. Now it's about 8:45. The first time I ran a full 5K on the treadmill (a month ago), my time was 37:08. I ran my first race last Sunday and I finished in 33:21. I have a 10K in May and a half in June and hopefully some smaller races in between.
And, I've converted to barefoot styled running. Vibrams. Look into them.
http://www.birthdayshoes.com has great information. It's the way we were supposed to run. Natural and barefoot. Running shoes didn't come about until the 1970s and there has been very little proof that it has helped prevent injuries. Also, the fastest runners in the world run in a style that mimic barefoot running. PLUS, it helps your body to naturally land the way it's meant to. You get a full range of motion, less knee pain, and you seriously work on your leg muscles. It's a beautiful thing.
Anyway, keep at it with running. It'll be difficult at first, but you can do it. Keep pushing yourself but remember to rest. Rest days are JUST as important so that you can improve and get better. Running started off as a way to help with weight loss but it has turned into something much more than that. I no longer focus on just weight goals but instead, I channel my energy to running. I can feel rewarded on a daily basis when it comes to running, whether it comes from running faster or farther or being able to sprint at some crazy speed. And, achieving that elusive runner's high is incredible. You just zone out and feel focused and amazing.
I love it. We are all meant to be runners. Maybe not the FASTEST runners. But runners.