Welcome to the X-Cart forums! Please start by reading the following thread, which will help you get started and hopefully make your experience here a positive one:
http://forum.x-cart.com/showthread.php?t=23970
Please note that this link is not an answer to your question, but we need you to update your signature with your X-Cart version so that we can answer your questions correctly.
Also, the thread you posted in was almost 3 years old. As old threads are no longer subscribed to, and usually relate to versions that are outdated, it is best to start a new thread rather than post in one that is more than a year old. I"ve moved your post to a new thread.
To answer your question, to add a class to a link, you use this format:
<a href="link.html" class="classname">link</a>
You'd then add .classname as a class in skin1.css.