First and foremost, an artist's website needs to have a clean aesthetic and easy navigation so that the focus is on your work, and little else. You need to begin with the best possible quality images (preferably jpegs). I prefer that viewers land on a page that immediately gives a feeling about the work. Therefore, the index (home) page is usually the portfolio page (or an intro page with a single image and links to all other major pages of the site).
You should also have a bio and/or artist statement page (or a page that combines the two). This way, if someone likes your work enough to read about you and/or your process, it develops more of a personal connection to the work. It's up to you whether or not you want to have prices on your work, or have them inquire for prices. My feeling is you are more likely to get some sales if that option is available. The easiest way to sell directly to the public is through a Paypal cart. All you need is a paypal account, and they only take a 3% fee on your sales for the convenience of using their secure site for payments.
Another thing you should consider having on your art site includes a links page (links help search engines find you, though it's more important to have others link to you than to have links going out... usually you gain links to your site by trading them).
It is also a very good idea these days to have a blog link on your site. The fact that they are constantly updated and include lots of links makes it one of the best ways to create traffic to your site.
Lastly, things to avoid: Stay away from distracting animations. Forget putting a music loop on the site unless you have the option of muting it. Be careful that the text is very legible by avoiding weird color combinations. Black or dark gray on white or light colors is the most legible, though white on black can also be very elegant.
I can tutor you to create your own site in Dreamweaver. If you are a self-starter, this might be the least expensive way to get a professional site. I can also create your site according to your specifications, then teach you how to update it.
