Hey JCooper! I was just perusing Butch's profile, and I saw your comment! I think I know what your problem is, and I had some trouble with it as well. On your profile, you can change your profile picture using edit 'profile picture' on the left of the screen when the User CP is up. The profile picture is not the same as the picture that posts with your name in the forums. To change that picture-like the hologram that Butch has under his name in threads, go to the User CP, and look at 'edit avatar' I think that's what you've been looking for.
And Butch is correct-If you want to post pictures in a thread, definitely use photobucket, as the GT attachments limit you to a few nice pictures.