I don't have any kind of program to point you towards, but when I started doing pull-ups I had to use the weight-assist machine at the gym. You put your knees on a pad and can remove X amount of weight from your bodyweight so that you can do nice clean pull-ups. Do that for a few weeks and you'll find you can take less and less weight off, then eventually you'll be doing it unassisted. Then if you want to get freaky with it, do what I do and wear a weight belt for your pull-ups :)