In Web pages, when you move the mouse over an image, you can see a description of that image.
Similarly, you can have a mouse over text for a link in your HTML page.
Here's the code:
<A HREF="http://www.somedomain.com/" TITLE="mouse over text here">Click here</A>
You need to give an appropriate text to the TITLE attribute. The text here will be served as the mouseover text.
This works fine with IE and Firefox.