So, I've downloaded the Creation Kit, haven't had any problems with it so far in terms of functionality, but as I've no experience in modding before now, I decided to work through all the tutorials. So I'm on pretty much the first Layout one, where you create a Nordic ruin, and I can't seem to find the ID for one of the pieces I'm supposed to be using.

Here's the piece I can't find the ID for:http://tinypic.com/r/21mrwc0/5 THe piece is the one with green all over it.

So am I just being an idiot or what? I really wanna get into modding but I think I'm gonna stick to the tutorials for now...the CK looks so confusing!

Duplicate the side walls on the opposite side of the room, rotate them around and place them.

If you watch http://www.youtube.com/watch?v=SO-OMWk0mQs you can see the layout demonstrated...

Duplicating won't work in this case as it's a big exit, NorRmSmWallFrontExBg01 Is what you are looking for.

Did you watch the video? Also watch the one that follows it. The answers are there

Let me briefly explain an example of the naming convention so based on what it is you have an easier time guessing it's ID:

NorRmSmWallFrontExBg01:
Nor- Nordic
Rm - Room
Sm - Small. This can be Bg for Big sometimes as well, or not in the name if there is no small/big variation.
Front - Room's sometimes have Front and Side pieces, these fit together with Corner (Cor) peices to form the perpendicular walls of rooms. Make sure the pieces fits, and if it doesnt use the opposite.
Ex - Exit, this means there is a doorway in the piece.
Bg - Big the door way is big. It can also be Sm - Small.
01 - It is variation 1 of that piece. Some wall pieces, for example NorRmSmWallSide01 will have many variations, like 1-4. If you look at each one, the facing of the wall may be shaped or textured differently to give a room variation when used together instead of using the exact same wall piece over and over.

Just about all of the kit pieces use this system. Like maybe, CaveHallSm2Way01 would be a 2 way (Corner) piece of a Small Cave hallway, variation 1.

Hopefully this helps you in the future. I don't know why they never explain it in the tutorials...