Great idea.
Get some books on the subject or google it to learn how to frame pictures and how to take interesting pictures.
Then start taking pictures. Lots of them. Keep the ones you like in an album so you can show prospective clients.
If I wanted to get started in this business, I might make the rounds at the local kids sports events. Take pictures, and bring them to the next game and see if you can sell some.
With the good digital cameras, you can take a movies and extract the best pictures from the movies.
I have an Olympus SP550UZ for this. It's about $450 at Walmart. It will take about an hour of video at the highest quality or about 10,000 pictures with a 1 gig memory chip.
You could also open a myspace account and post your best pictures there. Then you have someplace to refer people who might want to use you.
It sounds like an exciting opportunity. Hope it works out well for you.
You can order prints online or you can just take them to Walgreen's. I think you can order online and pick them up from your local Walgreens.