A lot of us have spent hours trying to figure this out only to be finally cued in and then said, "There needs to be a page about this. I would have never figured it out!"
So here is the instructions:
Go to the "Member Pages" page
and click the button on the left side of the screen - it is blue - that says "add a member page".
Title it "So-N-so's Swap Page".
Then start listing and adding pictures of all your stuff.
Copy and paste the link in the footer of your posts but still post it in the text when you are swapping because if someone is following the swap on a smart phone instead of a computer they can't see the footer information.