I don't know about videos but I know photos~ ^^
Oh the photos, you kinda have to be specific. But you see the little square with like a sun and a house and stuff its under the thingy where you move your words, you know what I mean? Like the paragraph thing that can move it to the right left middle and stuff? :D Under that click on the colorful little square and put a link into the URL space. The URL kind of have to be specific~ Hope that help~!! :D

Just copy and paste the image into the blog :)
but I'm not sure about the videos. Sorry ^^"