Hi Hawk,
Once you take a picture of your block and it is in your pictures on your computer, you just hit the reply button after someone has posted on the thread, then the add attachments button and then your pictures on your computer will come up. Then you check the pic you want uploaded and hit the button to choose it, then hit the send button. Don't preview it!! It gets lost in cyberspace!
In the pictures section on the board there is a tutorial thread you can read. It is titled how to post pictures at the top of all of the members posts.
Oh by the way ... Make sure you use a scant quarter inch seam with the quilter's cache blocks or you will come up short on the size. Ask me how I know this.... No, don't please.
I love the block you chose by the way!