Two most important factors in your design are the time it takes your pages to load and ease in navigation for your visitors. If your pages take too long to load, most visitors will become impatient and go elsewhere. After all, there are hundreds of websites in the same category as yours. Keep the total file size of your graphics 30 kilobytes or less per page. Create your site in such a way that you don't scroll more than 2 pages.
Long pages add to loading time.
Make sure you have your site hosted on a fast server. The easier you make it for your visitors to get around your website, the longer they will hang around. Your home page is the most crucial page on your site. This is the page that will either make you or break you. Be sure your home page tells visitors what your site is about.