engine head gasket

Hey I got a v6 stang. Can anyone tell me how do u know if you have blown ur head gasket. I know some of you might think this is a stupid question but i'm a person who knows very little about cars and here's another brain teaser how do u tell when ur transmission is slipping? Thanks.

Check for oil and coolant leaks around your heads
Oil gets into the combustion chamber and causes burning oil(blue smoke)
Check compression.
Check you coolant level and see if there is oil in the coolant and vise versa.

Try these first and see what you come up with.

I checked and there's is no oil burning and no mix of oil with the coolant or anything like that. What else should I check?

Why do you think you have a blow head gasket? Just wondering how the car is acting. If there is no oil/coolant mix and no smoke then I doubt its a head gasket. If the car is hard to start (gotta crank it forever) and its smokes when you first start it up or under a load you may have bad rings. Your trans will feel like it slipped outta gear and then back in, or it will not shift right from gear to gear. If you feel a real lose of power like you just put the car in neutral as you come to the top of a hill or incline then I would say yes it is slipping. If its an o/d then it has probably worn itself out shifting from d-o/d. What trans is it? I have rebuilt several and may be able to help with more specifics.