So, how does one embed a video in their "Description" with a video that's uploaded on youtube? I atleast know the simple task of copy and pasting the embeding code. However, I didn't see an html mode when writing the descriptions, so yeah. I've seen a few people do it so I was wondering how it was done...

Did you mean like my sig? With the rick roll?

Not a link XD. An actual youtube paste. Like how this person did...

http://www.tesnexus.com/downloads/file.php?id=19103

scroll down and you'll see the vids.

Oh, That is easy then... Just start a thread for the mod and go to it then click the "insert youtube video" button on the thread version. At least that's how I think it works...
EDIT:

OR... They could have done this in the long description: [(youtube)][(/youtube)] then just pasted the embed address in between the thing...

This link will give you the bbcode to allow embedding:

http://thenexusforums.com/index.php?showtopic=46616&hl=

Ah that covers it then. (Just need those two codes and put the embed code in between). Thank you Buddha and Deus Ultima~