Vincent Flanders' Web Pages that Suck blog lists the biggest Web design mistakes of 2004. He drew on his other weblog, the Daily Sucker, a blog that showcases current examples of bad design, to come up with 14 of the worst mistakes you can make when designing a website. Here are his top five:
1. "Believing people care about you and your website." People come to your site to have their problems solved. They could care less about you.
2. "A man from Mars can't figure out what your Website is about in less than 4 seconds." If someone can't figure out what you're about within 4 seconds of arriving on your homepage, you've failed.
3. "Mystical belief in the power of Web Standards, Usability and tableless CSS." In short, the tools you use are less important than how the site looks and works.
4. "Using design elements that get in the way of your visitors." He cites splash pages, animations, too much text, too many graphics, etc., as some elements that interrupt a user's experience -- and get in the way of the sale.
5. "Navigational failure." Flanders' says simplicity and consistency are key here. He even cites Seth Godin's weblog as something that fails in this category.
If you're in the midst of a redesign or designing your site for the first time, you should take a look at the points he makes. And jump into the Daily Sucker to see live examples of lousy Web pages. There's nothing like learning from others' mistakes.