If the video you're trying to put in is on youtube than it makes things really easy and you go to youtube.com and find the link to the video you want to post. then you go on here and on the posting screen (where it says font size, color, bold, etc.) there's an icon that says "You Tube" you click that and paste in the link to the video you'd like to post.
For photos one of the easiest ways is if you have a Photobucket account on photobucket.com you can just go there and copy the coding next to the photo you'd like to paste and put that on here. Another way would be to click the little icon on the posting page on here that looks like a tree and have the URL for the image you'd like to put on here and post that into the box that says image URL.
I saw all the videos in the new section and got very excited. I'd like to be able to put in my own ones too, but there's just one small problem. I have no idea how to embed things - both pictures and videos. Can anyone here give me a short tutorial and tell me the coding for embedding? Much appreciated.