I personally like to walk to music, and some good starter music is rock & roll (I like the oldies 60's & 70's stuff) which is a good walking beat. Later on if you think you'll stick to it, you may want to get tapes....Sports Music has the best.
As for a program, I think I walked less than 1/2 mile the first time. You just have to work into it. Do a warm up first, then just start truckin'. I work for time and not distance, so you may want to try 15 minutes at first, or 20. Just keep striving to go faster as you are able...keep pushing yourself.
As for form, bend your arms and pump them! Don't let them hang by your sides!!!! Take short steps and align them sort of like you're walking on a railroad track. The foot action is land on your heel, and roll onto your toe. Lead with your hips, and use that arm action to help you along. This is what is so good for your midsection. Really concentrate on what you're doing....pay attention to your form all the time.
They have videos on race walking at libraries....it may be a good idea to get one to watch to get your form down. This is a hard sport to describe!
It's very important to get good walking shoes...I wear New Balance now, but have worn Reebok Roadglider DMX, also.
Just like with any new activitiy....work your way into it. I walk two days per week now, and when I walk outside I try to get in some hills. If you walk at an indoor track, you could do some running intervals, or run up and down some stairs. That's what I do at my Y.
I don't know how helpful this has been, but I hope you try it. I've never had a walking related injury in ten years, and I know I can keep walking as long as my legs function.