I'm an experienced runner/cyclist. And I can tell you, there's no such thing as taking it too slow. Trust me, even if you start running 2 or 3 miles every other day, you'll see some benefits, and you won't risk injury.
Running is just one of those sports where it's pretty easy to hurt yourself. Not sure why, considering we're all bi-peds, and should be able to run w/o any issues, but hey. I suggest doing something like the following; this got me in great x-training shape over the winter.
Week 1 > M=20 mins / W=30 mins / F=20 mins
Week 2 > M=30 mins / W=35 mins / F=20 mins
Week 3 > M=35 mins / W=45 mins / F=25 mins
Week 4 > M=40 mins / W=45 mins / F=30 mins
... you know. Keep bumpin' it up as you go, or do the periodization thingie with a week of rest after week 4. You know what you like better than I do. But start with really low mileage. It's not the milage itself that gets you in shape, it's the consistency.