When i first started, i couldnt do more than 15 minutes on the treadmill, but we have to start somewhere, and starting out is always the hardest, to get to the point, where you feel half good about yourself and what you are doing. But having run for two years now, and running a 7.15 minute mile, having done the notorious Midsummer Munro ultra half, and not come last, i feel i am getting there, but its been a hard journey, but worth it.
Clothes wise, just make sure its not cotten, wicka material (think thats how you spell it). Just go to a running shop in your area, got to be one somewhere near. You need to get the right shoes, which means comfort, padding, and ones that arent going to ruin your feet.
I ran my first half in a cotton top, cheap shoes, and two pairs of socks. Being a beginner means making a lot of mistakes, but keep at it. You do start to learn. There is a great magazine in the shops for about 10 quid, its the beginners guide to running, lots of useful tips.
Keep at it, and it will be worth it i promise.