Assuming your pix are already uploaded to your page here...

All ya have to do is go to your gallery pic you wish to post and under the pic in the center (as I recall) it says "post in forum" or some such. Click on it and highlight (click on) the third line, then push and hold-down the Ctrl key while it is highlighted. While holding down Ctrl, press the C key. Now, release both keys and click on "New Comment" in your forum thread of choice, put the cursor where you want the pic, press and hold Ctrl again and press the V key while doing so, release both keys, again. VIOLA! Press "Submit Comment" as usual and you're done!!! Btw, I find it easiest to do this if I've two tabs open, one in the forums and the other on my pic gallery.