Ads are a massive part of how any site looks like. Despite the fact they can be pretty annoying they are sometimes the backbone of either a blog doing well or poorly. Therefore the placement of ad becomes a very important criteria while designing the layout of the site. For most of the people who are new to the blogging world, this can be a rather challenging task.
However, Google has always been extremely helpful when it comes to helping young bloggers establish themselves. They recently released this video which in great details tells how to go about the placement of Ads. here is the same video, hoping it would help you too to get the ads on your blog right.