Besides writing, I give people advice with marketing and designing their websites. Keep in mind, I don't actually do web design for others (this site, which I make and maintain myself, is about the limit of my skill there), but I know a ton about what makes a site or a sales-piece work.
I don't charge for this service - it comes as part of my writing fee (shameless plug).
So from my experiences, here are a few basic tips on website marketing:
Your customers came to your website because they have some kind of problem. You need to let them know, almost right away, that you can solve their problem. For example, I let you know right away that yea, I can solve your writing issues. Don't make people wonder if you can help them - let them know right away you have the answer.
Expanding on the above, many businesspeople do not know why their customers came to them. I wrote for a private investigator once. At first, all he wanted his site to talk about were his low rates, which I felt was a mistake. I basically had to tell him "Your customer did not come to your site to save money. Your customer came to your site because they think their spouse is cheating. SOLVE THAT PROBLEM. Your low fee is a bonus, and the icing on the cake."
I don't care how "cool" your website looks - if it is not easy to navigate, you will not sell anything. My site is easy to navigate. You can go anywhere from anywhere. Top links / side links. Either works fine. Little tiny links on the right? Not so good.
I have to say this again - The things you think are important are not the same things your customer thinks are important. Yea, I say this like three or four times on this website. It's THAT important.
I generally like a who / what / why / how approach. Tell me who you are, what you offer, why I need it (or you), and how it works. Of all these, you MUST convince me why I need your product (or why I should do business with you). Much of my writing is geared towards answering these questions.
Flash can be really annoying. Why annoy customers? Remember - your website is for your customers, not you.
Related to the above - do not force your customers to do anything, to watch anything, to listen to anything. If I go to a website and music starts playing (or a voice starts talking) I leave right away. Most web surfers do the same.
Do most of these seem like no-brainers? They are, but only when they are pointed out to you. There are people with Masters Degrees in Business and Marketing that ignore the above.