It's also awesome if you want to post a pic in a thread. Rather than uploading it as an attachment to a post, you can upload your image to your own album and it automatically creates a bulletin board image link (BB Code). Use that link by pasting it in your post. The advantage here is that the image appears in full size as opposed to the thumbnail that comes with an attachment.

The best way I've learned to use this stuff is to just try and make it work for me. I promise that if you click around and try things, it will not blow up your computer!