Here is the rest of the list.
1. Watch your load speeds. As a lot of people are on dial up, load speeds are an issue. No one wants to wait along time to have a page load. More and more are moving to faster connection speeds, but still a large percentage of people are still on slower speeds. While adding images or even thinking about video, remember load speeds.
2. Do not play music on your home page automatically. This has been mentioned by many books and design sites, yet still designers do it. For one most find it annoying when it starts, and two it can alienate people from your site because in various likes in music. I you must have music for example, a band site, give the user an option to turn it off, or have volume controls.
3. Easy to use navigation. This one is pretty important. Users want to know where they are and how to easily get to where they want to get. Make the site map of your site easy to read, and make the structure easy to follow. Also the navigation bar should be easy to read and consistent throughout your site or application.
4. Colors of text vs. background should be pleasing. There are always those sites that use red text over bright blue or something similar. Then you try to read the first line of text and go cross-eyed. Black texts on a white background is preferred, but if you need to use different colors, make sure the text is easily read, and does not strain the eyes.
5. Content. Write content for your site that is appropriate. Do not try to combine 3 businesses into one site as users will get confused as to what they are looking at. For example, if your site is about skiing in Aspen, do not try to run an online poker page from the same site. Domains and hosting is cheap enough to separate your business ventures.
6. Spelling goes a long way. Make sure you run your content through a spell-checker. I find even large corporate sites have very easy to fix spelling errors. Simple spelling errors put off users. If you can not spell right, it shows that a user cannot trust you with a product or service either.