Hey dude, not trying to burst your bubble, but it's best you keep all your pics in one thread.
Use this place called imageshack.us to make thumbnails so you don't have to upload to GTP all the time, and run out of space eventualy. When you've uploaded the pic to them, copy and paste the "Thumbnails for forums 1" onto your post and there, you have a thumbnail.
To add more pics to your post, press the edit button on the bottom-right of your post and you can add more.
