Runner's World has a great Beginners Section, including an 8 week plan to get you going.
http://www.runnersworld.com/cda/smar...-278-0,00.html
A mistake I made when I started running again 4 years ago was I told myself that I was an intermediate runner because I had run before (even though it was 2 years before that). If you haven't run in a while, you are a beginner, and need to train accordingly, or you will promptly burn out and quit.
I totally agree with Archaea. Don't worry about speed at the beginning, it's completely irrelevant unless you have an endurance base. Keep us posted.