First money maker program you can try is google adsense. This is a program from google that provide PPC (pay per click). So if somebody click the ad item you will get money, not much, but if so many people click, it will become much money :).
If you don't have account yet, you can subcribe here.
After that you can get the code and then just copy paste the code in your blog and wait the money come to you :)