Note! The instructions apply from version 9.1. If you have an earlier version, v.g. create a support case.
Note! This feature may not work correctly in Internet Explorer 9 (maybe even earlier versions).
However, the feature works well in Firefox and Chrome.
In admin when you write your category or product description (or create your own page in the CMS / Page and text manager)
you have an icon in the HTML tool that looks like a movie roll (line 3, third from the right).
By clicking on it, you can choose different ways to insert media.
If you e.g. to insert a Youtube clip, select "Iframe" in the "Type" menu. In "File / URL" enter the address of the youtube clip.
In "Dimensions" you write the dimensions of the ifram (it should be clear on Youtube how big the ifram should be).
Then click on "Insert" and have thus inserted your media.