What kind of shoes do you use now? Certain models are better, depending on certain factors, such as the kind of surface you run on, your weight, whether you over or under pronate, and which part of your foot strikes the ground when runnning. If you'd like, you can check out these sites, go through the shoe wizard, and then read up on recommended shoes:
http://www.runningshoesguru.com/best-running-shoes-wizard/ and
http://www.runnersworld.com/shoe-finder/shoe-advisor
How long did you run for? Since you're fairly new to running (according to the thread you made), you don't have to push yourself right away. You can warmup by walking for 5-10 minutes (or do dynamic stretches or anything to start increasing your heart rate), then running for maybe 20 or so minutes. As you continue doing this, you can increase the time you run. Interval training (run for a minute, walk for a minute; repeat 8-10 times) also helps; I would do this after I recovered from a sprained ankle, and still do it every now and then.
And a couch to 5k plan is always good for new runners.