I think that you'll find that emerge -k kde
will only get it from the disc (as in disc 2 of the 2 disc set!).
If you just did emerge kde
then it would get you all the packages, downloading 1 then compiling/merging it, then on to the next one etc etc.
I'll warn you now, It can take a serious long time to do it like this (mine took about 15 hours).
I would suggest that when you get home, you might want to go to the gentoo site, follow the "doc's" link and have a good look through the desktop installation guide - if you X server is ok, then you'd be able to miss that part, then when it get's to telling you about installing kde, it tells you about doing emerge kde first, but after that, it explains about doing it 1 package at a time, plus about just downloading the packages, and then compiling/merging them later.
If you tried emerge -p kde
first, that checks dependencies and tells you what you instalation will want you to download and install.
Oh, and when you look at the doc's, if you have a printer set up ok, and you want to have printed copies, you will notice that some of the doc's dont have the "printable copy" option. So it's just as easy to open the particular document page, then if the URL finishes with .xml change it in your browsers address panel so it finishes as .xml?style=printable and you will see the printable version and you should be able to just click on your print option.
Here's the links:
gentoo's main site
gentoo's main document section
gentoo's desk top guide
hope this helps
p.s. the desktop guide was produced when kde 3.1.2 was the dog's bollocks - obviously where it tell's you about modifying your XSESSIONS then put kde 3.2 instead.