Top Ten Mistakes in Web Design

Link to article (By Jakob Nielsen)
"The ten most egregious offenses against users. Web design disasters and HTML horrors are legion, though many usability atrocities are less common than they used to be. This article presents the highlights: the very worst mistakes of Web design.

1. Bad Search
2. PDF Files for Online Reading
3. Not Changing the Color of Visited Links
4. Non-Scannable Text
5. Fixed Font Size
6. Page Titles With Low Search Engine Visibility
7. Anything That Looks Like an Advertisement
8. Violating Design Conventions: Have Consistency! Jakob's Law of the Web User Experience states that "users spend most of their time on other websites." This means that they form their expectations for your site based on what's commonly done on most other site. If you deviate, your site will be harder to use and users will leave.
9. Opening New Browser Windows
10. Not Answering Users' Questions"

If you want to know more, I recommend that you read this short but very interesting, direct, and humoristic (cool cartoonish pictures) article by Jakob Nielsen a famous web design usability guru. Thumbs Up (Except for his website, ironically )!