I'm going to run a practical set of posts next week. They aren't strictly speaking "legally" related, but they will help you to avoid getting ripped off or scammed (and thereby needing to talk to a lawyer). These five tips aren't really even unique to Craigslist, but they are rules I've lived by for quite some time and I haven't gotten badly burned on any of several dozen transactions I've made to buy or sell things.
I can't speak about anything other than purchases- if you're trying to find Mr. Right or Mr. Right Now, find yourself another website.
The topics I'll cover are:
1. If it's too good to be true, don't fall for it.
2. If you need something NOW, go to a chain store rather than hunting on Craigslist.
3. Deal face to face- don't mail anything or accept mailing of anything.
4. Cash is king.
5. Know exactly what you're looking for (and where to find it).