Regarding the posting, We prefer using thumbnails so they don't take up too much screenspace unless clicked on, and then they open in a light box. Click on them again and you get them full rez.
To post your pic as a thumb, click 'go advanced' at the bottom of the message window and 'manage attachments' the rest is pretty self explanatory, although please note there are image size restrictions (both memory wise and dimension wise) but they're pretty big.
I've 'thumbed' your image for you.
All the best