The elements of your pages should naturally lead the eye from left to right and the entire home page should be visible in one screen. You should look at your pages using several browers as all browsers do not see the same things in exactly the same way. Your pages should load in 20 or less seconds, or your visitors will lose interest and move on to other sites. Be sure that all your posted links work properly. Get feedback from your visitors via guestbooks or e-mail links.
Content is important as well.
These are some very rudimentary tips that we sometimes forget. I give links to as many as I can find, and make them available free of charge to anyone who is interested.