okay so i went onto craigslist and found a guitar that i want but it doesn't have any contact information for the person selling the guitar. do i just email the Reply to: sale-___________ and ask them my questions about where they live and when i could come by and check it out or how do you get a hold of them?
Craigslist does that on purpose to keep your info private as a seller. If you want to post your info in your ad you can.

Send an email and ask your quesitons, just like you would here or on ebay.
It's a fine line between clever and stupid.