Craigslist works like any other classifieds. You list what you have, how much, and a way to contact.
Craigslist will put up a fake email which will redirect it to your real email. That way it's not plastered out there. Just put what you have, what games, and how much you want for it all. You should get between $30-$40 for the system alone. The games can be a hit or miss. Sports titles are always a dime a dozen, and ones with continued sequels like Call of Duty, where most of the game is played online. Since sony no longer supports the online play of older titles like that, the games themselves have no value, oh and movie titles are worthless. Disney puts out a lot of these when they release a new movie, or any big hit movie.
Here and there, you can find one worth some money. Platformers, like Ratchet and Clank or Sly Cooper, RPGs like Final Fantasy or Star Ocean, family friendly like any of the
Lego Games (Star Wars, Indiana Jones, Batman), these can all be worth a few bucks a piece. Not too much, but worth it to add some more to the price.
Make sure you hook it up and test it, and put that in your listing. List all games that are included, or at least list the type of games with a few highlights. Good clear pictures are a must, don't try cell phone pictures unless you have a ton of light to make it a good picture.