question about my 2000 ford mustang hvac controls!

I just brought a 2000 v6 mustang. I love this car! it handles great. I have a question with the hvac controls. I have max/ac, normal a/c, vent, floor, and mix. The book never says what vent or mix does. What does it do? To run the heater do I turn it do max ac and turn the dial to red? That works but I wanna make sure I doesnt damage my ac. Please help