Hi, I need some help.. When I go to my Timeline in Facebook, there are BIG ads there that I did not put on. Where do they come from and how did they get there? Is it something I've done that I don't even know that I've done?

How do I go about getting rid of these ads? Is this a new thing with Facebook?

I don't know much about Facebook and how to navigate around there. Can anyone recommend a good tutorial?