Well that is a lot to ask.....
first of all learn where ever you can about
SEO it is not that hard to understand, but it can be a pain in the ass sometime, there are few thing you need to know.
then find a niche that you like and know as much as you can about your merchant.
If you know how to buy a domain and put up a site do so, if not find yourself affiliate program that provide you with a whitlabel or that works with downloadabel templates.
and start promoting, exchange links add keyword post on blogs and forum etc..
just jump in to the water you will see that the water is not that cold

good luck.....