I’m a web developer. I’m a Yahoo! Small Business Partner and do mostly Yahoo! Merchant Solutions Stores. I generally avoid designs that use a large, single graphic because they take so long to load, too much of the page is graphics which are invisible black holes to search engine spider eyes, and they are too difficult for site owners to modify.
That said, the graphical look and feel of a site is vitally important. You can’t grab visitors with text alone. Text is vital for SEO, but it won’t win click-throughs for you. Web research shows that users decide whether a page they land on “has what they are looking for” in 50 milliseconds. They may linger quite a bit longer, but if their initial impression was that “this ain’t it” they almost always back button out to the search engine that sent them, and try someone else’s site.
Your graphics skills are valuable. A top notch developer could guide you in what to do, and use the graphics you develop. If you want to go it alone, you need to learn HTML, CSS, JavaScript, at least one Web based query language such as PHP or ASP and an appropriate database such as MySQL or Microsoft SQL. You also need to learn about Search Engine Optimization (SEO) and human engineering (designing in calls to action to get visitors moving through whatever the site’s purpose is; making sure the user interface is stupidly obvious and easy to grasp, yet fun; etc).
I’ve had external graphic designers forced on me by a couple of clients, and each has been a headache. The graphics people generally understand almost nothing about web design, usability or SEO. Get a leg up on those issues, and you will be way ahead of the pack. Best of luck. If you’re interested, PM me with a link to some of your work.