I'd personally recommend SuSE's documentation (you know, the two huge
books that came with the CDs--unless you installed by network). The user
handbook is a rather soft introduction into KDE, Gnome, printing, GIMP,
sending Mail, etc. For a newbie, it's very illuminating. The admin
handbook is made from completely different stuff. This will teach you a
lot about how to do really funky stuff to your system. If you've got
several hard drives, take a look at Logical Volume Management. Of
course, the SuSE manuals don't teach you how to do stuff by editing text
files, so I'd still recommend reading the other stuff people mentionend,
just in case YaST doesn't do as you tell it to.
Good luck!
Andres