[CentOS] Yum update without internet connection

I usually use a "Desktop" option when installing a new machine. This 
gives me all I need for an X session and then I add other packages or 
grouplists on an as-needed basis.

I'm putting together a couple of machines that will not have network 
connectivity until all packages are installed. Is there a way to run yum 
to install packages/groups from the installation disk instead of from 
one of the normal yum repositories? If so, is there a ever a problem 
with packages on the second disk of the 2 disk installation DVDs?

Thanks,

steve campbell