fake-a-lake

So I decided to winterize my own boat this year rather than take it to the dealer. It's a new Pro-V so I'm not too worried that something will need to be changed. I live in Oklahoma and many days during the winter months we'll have fablous weather 60s so I might want to take the boat out before spring hits. So I bought a fake-a-lake and have some other general questions about other things I might be missing. First question, how much antifreeze should I put in the five gallon bucket? I have a heater should I use special concern with it or should the antifreeze make it through there as well?? I know it should but never done this myself. Should I do it on a flat surface or should it really matter?? What other considerations should I keep in mind?

Thanks for any comments that will assist me.