Can you tell me from experience what you asked when you hired someone to post messages on facebook discussions, group, wall, and pages. I wqant to know because so I can ask the contractors the best questions and look like a pro doing it! Just give me the questions you asked (without the usual stuff) that you considerd most important to get the answer to.
Basically never ask anything, first check out what is he/she offering you. After you have couple of the people replying with their services, you can compare them and simultaneously ask the questions