So you want to have a gallery. It is a great place to keep pics that the players (and maybe the GM <g>) will want to refer to from time to time.
First you have to let the crack Admin team that you want a gallery for your forum. The best place to ask is in the thread where you asked for your game. But you can post a new thread asking for it too.
Once your new gallery is created, you will want to add pictures. Go to the gallery, click on 'New Image' near the top a bit to the left of center. Enter any 'subject line' and 'description' in the text boxes then click on 'image manager'.
Enter any 'caption' that you want for that pic (you can enter that later if you want). Next go down and click the 'browse' button. That will open a 'browse window' showing the files on your PC.
Locate the file on your system that you want to upload. Click on that file and then click 'Open'. That will take you back to the image manager. Now you can 'edit' or 'add' caption info before you click the 'add' button.
1.) Don't forget to click the 'add' button (the last item above). Your file won't be added otherwise.
2.) Images cannot be larger than 1 meg in size.
OK ... once you click 'Done adding images', you will be taken back to the post and you should see, just to the right of the 'image manager' link, a list of how many images you have added. If it shows 0 or the wrong number of files, you forgot to click 'add' for one or more <g>
If you are happy with the subject and the description, click submit, just like a post.
Hope that helps.