What are the proper things to do before launching my boat?

i own a 22foot baja with a 200 mercury xri, and it will be my first time running my boat.. i dont know anything about it.. what are the proper things to do and check for before i put her in the water? i need to know what to do all the way from the fuel and what to mix in with it. to the pumps to the lights.. i need to know everything.. please help