I'm trying to replace my aged Macbook for the new Ipad. (a daunting task to say the least)

I can't figure out a way to post a photo from the ipad to this bulletin board. On the Macbook I'd format a a photo, put it on the desktop and then select it in the 'optional image filename' (choose file) area. That can't be done on the Ipad as there isn't a desktop.

So,, what's the best way to get a photo from the Ipad to this 'Bulletin Board'? This damn thing is driving me crazy but I'm really intrigued with it.