resize your images for message boards here
http://imageshack.us/On that link, you "browse" your docoments for your saved image, click "host it", next page appears and you scroll to bottom and copy "Direct link to image".
Now, on THIS page, click on the "insert image" icon (2nd from left just above the smileys) which will appear in this white text area as:
(img)(img)
then you paste what you copied ("Direct link to image") exactly in the middle of (img)x(img)
Its not ez to explain but I tried.