-Click on "User CP" (Next to FAQ, on the green bar near the top of the screen)
-Then Click on "Edit Signature"
-Put in the code: [ URL=http://img194.imageshack.us/i/meganfoxcopya.jpg/][ IMG]http://img194.imageshack.us/img194/4633/meganfoxcopya.jpg[/IMG][/URL]
^Just remove the space in front of the first [URL] and the first [IMG]