What should i do in order my users can create there own shop in my website. like ebay etc

hello to all.
i hope i got the correct category

Am about to build one very unique classified website in my country and one of my advantages is going to allow users to create there own store feature, i have already the option to visit each users personal profile and view all there advertisements, but this is not that good for me, i want them to pay a little extra fee so they can add there own paypal button add there own nice banner on top etc.

is there any article or post that i can start reading?
or anyone can give me some hinds where to start from??

thanks team
chris