Hello All, I posted last night but must have done something wrong, can't find it,

I have been using Calibre for a couple of months now and love it, am just about to receive my Sony reader PRS T1 any day - a gift from my partner in the US
I want to share some books with him, he's just about to install Calibre.
My question is, how can I keep the metadata intact?
I tried creating a second library on Calibre to experiment, but when I copied the books in the metadata was missing.
I know he can do this himself, but he works so hard, I'd like to be able to do it for him.
I appreciate your advice, Cheers!