See that little "Folder" icon above all the smilies? Its the last one. Click that and it brings you to your library. Then you click on the circles in your library to post which picture you want..
Repeat for adding more pictures. You have to press Enter after doing that so the pictures go down the page and not across.
Harold, here is a free program that works great to resize your pics.
Simply right click on the file name, (no need to open the picture) and choose "resize". In the case of this site, it likes the "medium" option. It will instantly re-save the picture with the same name and the word medium next to it. Then upload these medium pics to your library and your good to go...
I was thinking of doing a member project and posting the steps. I can do the photos, I just didn't see a way to upoload something to the projects section. Sorry for the hijack.