ANALYSE COOKIES FROM CRAIGSLIST.ORG

Hello! I need someone who understands how cookies work. For someone to post ads on Craigslist ([login to view URL]) the site requires that the browser, being used to post, accepts cookies. I'd like to understand what kind of information is being sent to Craigslist through these cookies. More specifically: 1) what information is being stored on my computer; 2) what information is being sent to Craigslist; 3) any thing else that the coder might consider valuable information.