This one is actually going to be typed.
Just a warning.
So. You have a blog, and figure that if youre already doing something, it might as well be giving you money for doing it. So, this is pretty much how.
The main way to make money on a blog is with ads. There are several different ad programs you can use (clicksor, google adsense, adbrite, yahoo marketing, etc.) however, the only advertising site I can actually condone the use of is bidvertiser. Im sure the other sites work just fine for some people, but they didnt work out too great for me.
The advantages of bidvertiser are mainly that, you can filter through the ads to choose a price range, they actually attempt to find content relevant to the blog, and they arent as finicky and paranoid as Google ad sense.
Second, dont make a blog for ads. If you actually enjoy blogging, then do it. This is just a way to make extra money on the side. If you want to sign up, I will post a referral link (another advantage) and a non referral link.
Referral: Monetize your Website or Blog with BidVertiser
non referral: bidvertiser.com