Could I have a CD key please and thank you.

Go here, and where it says "problem type" , select multiplayer key request.
http://www.gog.com/en/support/contact/technical_issues_with_games/neverwinter_nights_diamond_edition

Disregard what olnorton said: you can go to your account via the website, click on the game on your shelf, click the "More" dropdown, and click "Serial keys". There they are. :) That's no longer necessary. :)

Excellent. This should really be in the sticky above.

It is. ;) It was edited into the OP of the locked "CD-KEY info" sticky.
EDIT: Corrected thread title.

They should probably put something on Page 10 as well.

Because when I clicked on that thread, I was brought to the last page...

Or better still, remove the 10 pages and just have a sticky with only the current method.

That's because of your forum preferences. One of the first things I did when I started using the forums was change it so I went to page 1 of a thread.