To answer the OP's question...
If you are going to start a business, you really need an SLR camera. A point and shoot just won't do.
I am getting ahead of myself though...
The very first thing you need is a Logo. Every business has a logo. They can take time to get right, so concentrate on that first.
Then after you have a logo all sorted out, get a facebook business page that you can put your logo on.
Now you are ready to start taking pictures. Post your pictures on facebook for everyone to see.
Then you can advertise on Craigslist, and point people to your facebook business page. Here they will see your logo, and know you are a pro. Then they can see your photos, and they will hire you on the spot.
So start getting all your ducks in a row...Logo first.
Oh, and take some pictures of ducks. Everyone loves pictures of ducks.