Is there any way of making money when someone is visiting my blog also?
In terms of Adsense they render two type of ads (and no, you can't choose which type you get :) ~ pay per click and pay per impression. They're pretty much self explanatory; with pay per click you get revenue each time someone makes a legitimate click on an ad and with pay per impression you get about a Krona or less for every 1000 times the advert(s) appears.
Pay per click easily generates the most money and you can expect to get about 1-3 clicks for every hundred or so visitors which means you need to be getting 1000s of daily visitors to make even a modest amount of money. It is worth it but can takes a few years to build up that level of traffic to reap the (again modest) rewards.