Okay, I feel really stupid asking, but after slogging through 7 pages of help threads I still can't figure it out.

How do you make yourself a signature? Where do you go to edit/make one?

Click the "edit signature" link that's right underneath your forum post :)

To make a link there are 3 ways, all of them use the forum BB code:

Plain link;
{url}http://www.drunkduck.com {/url}

Named link;
{url=http://www.drunkduck.com }Drunk Duck{/url}

Picture link;
{url=http://www.drunkduck.com }{img}http://www.drunkduck.com/gfx/avatars/avatar_12163.png {/img}{/url}

Substitute the link test, name and image link for your own. Replace the curly brackets with square ones and the links will look like this:

Plain link;
http://www.drunkduck.com

Named link;
Drunk Duck

Picture link;

Oh, right... I feel even stupider now.