Alt+R is the default key to start recording (and also to stop the film). Recorded films will be in your Aces High II\Films folder (C:\Program files\HTC\Aces High II\Films or where you installed the game). Then you have to quit the game and start the film viewer, should be in the "Aces High II" folder in your Start menu. Open the film, view.. I don't know that much about editing though, there are people here with much more knowledge about that. You might want to check the Films & Screenshots forum for that.
I hope this gets you started.
