CSS - force divs to align beside each other

This is my first post, so I will start with a little bit simple problems.
Did you ever had problems when aligning DIVs, for example, you want to put the video clip on the left side, on the right side you want to put some description of the video.
I had this problem a few days ago, when div's didn't want to align beside each other. With a little bit of searching over the internet i found some simple css properties to do that, so let's see how i solved this.