While you're at the academy, you make near nothing, in the ballpark of $8/hr. You do get per diem though, ~$30 for food and ~$50 for housing. Food alone comes to about an extra $900/month. Your academy training length can very depending on your background.
I'm going in OTS(Off the Street) and will be there from Dec 4-April 15, 84 classroom days. Once I PV(Pass), you move to what's called AG pay, which is $37070 + locality. It just going up from there.
In the main ATS forum is a post from Cheezypoof called 2010, 2011, 2012 pay bands.
http://forums.jetcareers.com/air-traffic-control/95581-2010-2011-2012-pay-bands.html
Pay is based on the level of your facility. New York is level 12, nice. Colorado Springs is level suck, not so nice(to me anyways, YMMV). Some people prefer smaller places only open 12 hours a day(pays less, not as busy), other prefer 24 hour places(busy all day, every day), your call.