If you simply insert a URL into your post it will automatically show as a clickable link but will show the URL as the link's text.

Some people like to have the link be described, though, like so.

How to do that would be to select the "URL" button above the post's text box.
- It will show like this (without the asterisk): [url*][/url*]
- At that point you will put what ever text you want to describe the link, for example: [url*]like so.[/url*]
- Then, to insert the actual URL, in the first URL tag you will put an equals sign after "URL" and then you will put the URL, like this: [*url=http://milehighbugclub.com/index.php]like so.[/url*]
That's how I got that link in the previous paragraph.