How to switch between diff. window managers

[The Rock]

I'm running Slackware 4, and being a complete Linux newbie, I didn't try to pick and choose which things to install when I first set up Slackware. I just downloaded everything in the /linux/Slackware4-0/slackware directory at ftp.cdrom.com and installed every bloody thing. What I would like to know is this: can I use more than one window manager? By default, Slack uses KDE (it seems that way). I like KDE, but I hear things about Gnome and others, and if I could start up a different GUI with a simple command, that would be a great way to get my feet wet with some other Linux GUI's. I also wouldn't mind finding something a la "the complete newbie guide to Linux" on the web somewhere. If someone could point me towards one of those, I'll be asking a LOT less dumb questions. :-)

The Rock