Here's my standard blue-clicky example:

<a href="http://www.mudcat.org/">Click here</a>

<a href="mailto:joe@mudcat.org/">Click to e-mail</a>

If you're posting links at Mudcat, the quotation marks are optional. I prefer not to use them, because they complicate the task of making links. Simple is better, I think. Fewer misteaks.

This thread (click) will tell you absolutely everything you need to know. If you just want the basic stuff, take a look at the Mudcat FAQ.
-Joe Offer-