Good question man!
CTR means how many people that look at your page view it.
No idea, I just signed up for it myself. I doubt anyone can make any real money on this unless you come up with a super original website.
Uhh I believe its how many views you get to ad clicks or something... Not exactly sure either but there is a bunch of helpful articles if you want to try and google the question
10:1 Views to clicks. That's average. But you want 15:1. Keep CTR low.
Page Impressions = how many people have seen your pageClicks = how many ads have been clickedCTR = Clicks / Page Impressions
Joe is right