[TriLUG] Red Hat Enterprise Linux and installing more packages

[Rock Roskam]

I am installing RHEL 3.0.  I am spoiled by yum and fedora core.  Are there repositories to use yum on RHEL 3.0.  On a side note how do you use the application installer to install additional package groups like development from a mounted iso image.  It keeps wanting me to insert CD-ROM but not letting me choose the mounted iso images.    Thanks for any feedback.
Rock