Make text into a link

If I wanted to make some text link to a page in something like a signature or on a forum post, etc... How do I do this?

Most of the time forums, especially with signatures, don't allow HTML either.

You would use a hyperlink:

The code for that is:
<a href="websitehere.com">Text you want to see</a>

But for most forums and signatures, there is what is known as BBcode that will take care of that for you, so as not to confuse the HTML within the PHP of the forums.