Inside of the text editor you select the type you want to be a link then click the paperclip (link button), then type in the site URL. and click save.
Example: I want my name to link to this website it would look like this in HTML:
<a href="
http://www.experts-exchange.com">jeremyja
red74</a>
if it link from one page to another in your own site you can leave off the
http:// Like this:
<a href="/experts-exchange.co
m">jeremyja
red74</a>