OK the next step is to plan out the prizes, because that might take you some time to gather up.
IMPORTANT NOTE: IT IS AGAINST FACEBOOK TERMS TO USE FACEBOOK TO SELECT OR AWARD PRIZES. You absolutely cannot ask questions in Facebook and choose a winner. You can't say "first person to guess" or so on. That would directly violate Facebook's terms of service and could get your entire account shut down. Don't risk it!!
You MUST use an external app to do any prize selection. I did testing of several of them. The one I liked was RaffleCopter which is FREE. It plugs into your Facebook accounts and handles all the legal stuff for you properly. You can see a RaffleCopter entry here -SuttonMass page with RaffleCopter Contest
It's the icon that looks like a helicopter.
I'm going to set up an entry form on my LisaShea.com website, because I know how to code and that way I can make it just the way I want it to be. I am familiar with contest legal issues by now and know to include the start and end date, the value of the prize, a description of the prize, a statement that only US and UK people can enter, that only those 18 or older can enter, and the other legal language necessary. To see what a contest page should entail, click on our Trivia Contests
page here at BellaOnline and look at our rules. You want your rules page to look like that.
If you'd rather not code a page on your own website, definitely go with RaffleCopter or another choice. But make sure you DO NOT USE Facebook itself to draw names. After all the work you've put into setting up and promoting your Facebook page, you don't want to be shut down.