I would read a few books, maybe join a running club or at least download a running programme to stick to, there are hundreds on the net. From couch to 5k, to plans for running ultra marathons.
Just try and get into a routine of running regularly, ensure you warm up properly and are giving yourself time for recovery.
Set yourself a goal, e.g. I want to run a 10k in 12 weeks in under 50 minutes etc etc..
Interval training helps (fartleks), doing this one day a week will really help with your speed and endurance.
I tend to run 3 days during the week and the do a long run on Sunday mornings. The thing I like about running is that you improve slowly and it's incremental.
Get yourself a decent pair of shoes, go to a proper running shop, have them look at your gait and then you can find a pair that are suitable cheap on line. I would love to support my local running shop, but they charge three times the amount that internet stores do for the same pair of trainers! I recommend Mizuno, Asics, Brooks.. Nike Air Pegasus are nice and light as well.
Get yourself a decent running belt as well if you want to do distance running, as you will want to ensure you have carbs etc with you at all times.
This site is good for the diabetes side of stuff..