The fastest way to injury when starting a running program is doing too much and going too fast.
You need to ease yourself into running. Warm up well before you even start running, walk quickly for 5-10 minutes-not a stroll but a serious walk were you feel your leg muscles getting warm.
Most beginning running programs start out with a warm up, then several run/walk sequences depending on your experience and what you can do, then cool down and stretch. Always stretch warm muscles, not cold ones.
You should be running at a pace where you can hold a conversation. If you are out of breath you are running to fast.
Here are some good articles from coolrunning.com for new runners:
Couch Potato to 5K program
http://www.coolrunning.com/engine/2/2_3/181.shtml
First steps
http://www.coolrunning.com/engine/2/2_3/182.shtml
An Ounce of Prevention
The best fix for running injuries is to avoid hurting yourself in the first place.
http://www.coolrunning.com/engine/2/2_5/230.shtml
Have fun. I started running in April and it's been great.
Sarah