If you pre-ordered, you must enter your pre-order key first, then your CD-KEY.
EBGames will be sending out, via e-mail, pre-order keys.
If you have already entered the cd key, like I did (Turbine said it was ok to do it out of order -- they LIE!!

), then enter the pre-order key, then go in game and do an urgent assistance and you will get your second gem.