BleepingComputer.com: Any ideas

Hello

I am just wondering if anyone knows of any free software I can utilise to add to my social site on ning so that members from my group can add items for sale and add a photo of goods they want to sell. This is a non profit organisation and items will be sold not for profit but the items can be bought in return for a donation to our chosen charity "The Mermaid Foundation" supporting young adults with difficulties.

I have tried searching the web but its all a tad confusing.

Thank you
Sophie