Hi Dave - you're around the same height/size/weight as I was when I started in November, though a few years younger.
I started with a copy of "The Beginning Runner's Handbook" and followed it's 13 week programme - due to a couple of weeks when I wasn't up to running, this is my final week, and I've gone from being decidedly wheezy at a run 30sec, walk 4:30, repeat 8 times to a 10k run on Thursday that I'm properly looking forward too. It's not gone to badly, and I'd highly recommend the programme, it pushes just enough.
Good luck, hope it goes well!