To add photos make sure you upload them to the EA server. Just saving them after the game won't do it, you need to manually go to My Highlights. It's the same area where you can view your Trophies and Achievements (you can do it while in the OD or from the main game menu). A folder will be created for each game that you have a highlight saved for. Choose the game you want, but you can only upload 3 photos to the EA server. If you try to upload more than 3, it will automatically delete whichever photo is oldest. What I do is after I upload the pictures, I then save them to another photo upload site (imageshack, photobucket, tinypic, etc).
Once you have it saved, to actually insert it into the forum, type this
"["img"]"direct_photo_link"["/img"]" Do that without the quotation marks, though. The file will have to be in .jpg format, but all those sites will do it automatically, and pretty much any image you have saved on your pc or you borrow from another site will also be saved that way.
Then you are good to go