There are somethings that you should never do when building a website. Here are a few of them.

1. Underlined text
Underlines are for links - not regular text. Don't underline things as if you do they will look like links which just confuses visitors because they don't know which ones are links and which ones aren't.

2. Capital letters
It looks so tacky when the description of the items on eBay is all in capital letters. Don't do it! It really does look terrible and its harder to read.

3. Visited links
Don't have a different link color to your visited links color. If you click one link, when you go back to that page the link sticks out like no ones business. Keep them all one color.

4. Framed links
Never ever add a frame to any sites you link to! Open it in the current window, open it in a new window, whatever just don't frame it. It is annoying for the visitors and if you click "close this frame" (also long as the frame even has one) it takes you back to the original page and not the page the visitor is currently on.