If you watch the Band Of Brothers series the episodes are accompanied by interviews with the men portrayed. One (I forget who) explained that volunteers were sought for the Airbourne.

Who wants to volunteer for the airbourne?"

They didn't know what it was, it was explained "You jump out of airplanes to fight".

"Go to hell", nobody put their hand up.

Then I don't know what it was bought it up, but the guy giving the speech says "But you get paid $50 a month more"

That made it $100, (he then raises his hand).

If you want to learn about the training you could do a lot worse than watch the Band Of Brothers series, the first couple of episodes are all about their preparations for war. Meantime this gives a little taster http://youtu.be/z6j_nop4wh0

The British paratroopers were also volunteers, I don't know if they received higher pay.

There is a little about the formation about airbourne units here: http://www.historynet.com/allied-airborne-forces-in-world-war-ii-surviving-the-devils-cauldron.htm