Yeah, I've been into this stuff for a bit now, and you really won't make any more than chump change unless you get a few hundred THOUSAND a month.
But here's a quick lesson, there are three methods of payment:
CPC: Count per click, which as its name indicates pays you for the amount of clicks you get. Some examples include eads.com or 1for1.com They typically pay $0.10-$0.15 a click.
CPM: Count per thousand (M representing the roman numeral for 1000), which pays by a certain rate per thousand visitors. These days these rates are pretty low, ranging at less than $1 at times. Unless you have a LOT of traffic, say a million+ a month, you really won't get much. Example, say you get 100,000 visitors in a month, and the CPM rate is $1, you get $100. Sometimes it COULD get really high though if you get a lot of traffic and a good deal, like $10.
Another is pay by commission, which includes services like Paypal, where you'll get $5 for each single person you refer. Not too bad at all..