Hi Jackie,
Welcome to 5 Star and thanks for posting your question.
Do you have any knowledge of site building and html???
If you do then A suggestion would be to start with a template from
http://www.goldenpinecone.com/affordable-templates.html. Many of the templates are designed specifically for affiliate marketing. The owner is a professional affiliate marketer. She also does custom design, so thats where I would start.
The key is, you need to have someone design it that understands search engine ranking and builds a site that's good for the consumer as well as for getting good rankings. Some designers are only good at the cosmetics and their sites cant even be read by the search engines.
A GREAT FREE way to get started may be to consider a blog. You can build a blog at blogger that the search engines will love, choice of great designs, not programming required. Almost as easy as Word. Then you can transfer that blog to your new domain name. Honestly if I was just learning, thats where I
would START. You may not make a ton of money that way but I think it's one of the best ways to get started and begin to learn the ropes.
All things considered there are MANY ways to get started and other people would recommend other ideas. To a large degree, the "best" way to get started depends on your circumstances. More $ than time??? Then find someone to build a site for you, just be sure they understand SEO and affiliate marketing. More time than money? Then take the time to learn to do it yourself. In the long run you will probably benefit from learning to do it all yourself, but it may take longer to generate profit that way.
Those are my initial thoughts. Anyone else?