to post photos, the easiest thing to do is get a flickr account (at flickr.com)
upload your pictures there, then copy the image location.
go to the thread you would like to post in, hit the 'reply' button instead of the 'quick reply'
above the line of smilies, the second button from the right is the 'insert graphic' button.
click on it and these two brackets will appear.
[img ][ /img]
in between these two brackets, paste your image location.