This is the third time I'm writing this but Armaholic screwed me over when I tried to reply got a script error or something.
I'll have to start writing this again...
Well I'd recommend you play around in the editor and place your plane/helicopter and fly around, learn to control the airframe as much as you can, it's very important that you learn how the airframe handles, how much dive it can take how much power it takes to lift and so on.
First thing you should do for helicopter is just to fly around, first thing would be to learn how to land and start.
After you've mastered landing and starting you can start flying low and try to control how much power you need to maintain your speed and altitude, it's very important that you learn to fly normally before you start doing combat missions with enemies and what not.
After learning how to master the control and power, you need to start landing in tight spots, still flying low and always practicing. Basically when you feel comfortable with it you start flying with enemies around, you place a few APC's or maybe cars around and try and kill them obviously, always controlable flying, don't dive down 90 degrees and drop a bomb, make it so that you always know what you're doing and you're always in control.
First thing you'll have to do in publics, is often transport duty. Now that's something that you need to practice as well. Flying safely and landing quickly if required, what's good practice is also destroying your tailrotor or engines while flying with scripts so you can learn how to crash land without blowing up.
I have a youtube page which is OksmanToH. In there you will find a playlist called Tutorials & Guides, you go into that one and I should have about 5 tutorials for flying.
So read up and check those videos!
Lazy link to the playlist: http://www.youtube.com/playlist?list=PLC6C06B11D48AEECD&feature=view_all