Four Devices

I have to iPhone 4s and a MacBook Pro and Air, all running Mountain Lion and iOS6. I would like to have each device be able to communicate with the other on facetime and messages. All devices have one apple ID and password. The two iPhones have individual phone numbers. Each computer has its own gmail account. I also have a me.com account and several alias from that account. I am totally confused on how to set this up. Please step me through by the numbers. Thanks