Be original. Make your own graphics if possible. Even if you can't afford your own graphics program, you can download PhotoPlus for free here. There is another great graphics program called GIMP that you can also download for free. Your own graphics make your site one of a kind. No one else on the planet will have a site that looks like yours.
Have good content. Try to present your content in a way it hasn't been presented before. Come up with a common theme that will run throughout your whole site. Try to specialize in one area and learn as much about your subject as you can by going to your local library or browsing internet sites. Be sure to credit your sources properly.
Have a consistent color and graphics theme throughout your site. Each individual page should look like it belongs to the whole site. Pick out an unusual font that you use through your whole site.
Have a good navigation system throughout the site and keep it consistent. If your navigation system is the same on every page, people will have an easier time figuring out how to get around your site, especially if it's a large one.
Dont's:
Don't use too many animated graphics or "under construction" signs.
Don't make your text too small or the same color as the background. No one will be able to read your text.
Don't use frames if you don't have to, use layers or tables instead. Search engines hate frames.
Don't plagiarize (reproduce someone else's work word for word and pass it off as your own). All of the following examples were found by typing one or more of the sentences from my Web site into the Google search engine, every single one of them is in violation of United States copyright laws for stealing my work: