New install and newbie questions

[Charles]

I've just downloaded and installed the "sarge" distribution on a computer I use for a test bed.  Since I'm used to hosing this box and reinstalling to learn more, most of the hardware present is fairly generic and well supported across both Linux and Windows.   So far, I have network connectivity and throughput on my DSL router for broadband access.  I have a basic load of applications installed.  Mozilla works fine, so the desktop, GUI, and network connectivity are OK.   The character-based installation threw me for a loop, and I have rather a few more questions based on previous, now false, assumptions.   1)  Is there a command line or series of command lines that will update the fresh installation with all outstanding security updates?  I've become accustomed to using urpmi, and this is different.  What I would llike to do is issue these lines to insure I have an up-to-date system.   2)  Same as #1, but for bug fixes on installed packages.   3)  What can I do with the 14 CD's and two update CD's in order to integrate them into the system?  The default GUI is going to be set to KDE, and KDE has kpackage which I remember from previous distributions and which also recognizes the Debian format.  My eventual interest is in being able to install and remove packages on the fly, and I understand the 14 CD's comprise all the software available and specifically modified for Debian.   4)  Is there an online resource that will start walking me through the differences between Debian and, say, Redhat, Mandrake, Suse, or other distributions?