I'm doing my first sale this week, too.
To post the photos, click on "browse" at the bottom of the topic page, then "open" the jpg picture (that's what I use, at least)and attach it.
Interested buyers will PM (personal message) you, and you keep track of who asks first for each item and reply whether they get what they requested.
I gave my home address in reply and asked for a check or MO, since I have no experience with Paypal.
Hope this helps!