Ebay-style input for a web site

[yakkbls]

hello everyone.

i have a question and would appriciate some ideas.

i am making a website for local ads. i would like to have the site set up so that the user can input all their own information about their ad, put a picture, and most of all, pay.

i guess what im trying to get is that i want it to be like ebay's setup. the end-user is responsible for all input.

if anyone has any software that would help me, that would be great. ideas are welcome.

thanks.