This is how it works post an item, description and price first person to comment has dibs and it goes in order of interest from there. You don't have to hold items but you need to give buyers a reasonable amount of time to respond and pick up! If posted on another site you must state that in description and keep your items updated. When your item is pending pick up post ppu after it picked up tag a administrator to have it deleted! If you are advertising a service you may only have one advertisement on the page at a time if you would like to post a new one you need to ask for the old one to be deleted! Bump all you want! Follow the guidelines or get deleted its that simple =)
And remember HAVE FUN!!
HAPPY BUYING AND SELLING!!!