deano - go into your "User CP" at the top of the screen, then on the left "edit signature", and enter what you want, and then save it.
If you want a link to your tank thread - copy the below code into your sig and then put a [ right at the beginning (right before URL) and a ] at the very end.......
URL="http://www.reefsanctuary.com/forums/red-sea-max-owners-club/56872-side-winders-reef.html"]Side Winders Reef[/URL
and it will look like this:
Side Winders Reef
There are other ways to do that, but that may save you time, and save me some typing LOL!