First, you will need a seperate drive / partition for Linux.
Then, start with this Tech Republic article:
Try this helpful workaround for a Linux/Win2K dual boot
Jun 25, 2001
Mike Walton
This site, is referenced in the article:
http://www.tldp.org/HOWTO/mini/Linux+NT-Loader.html
This site is for Linux multi-booting:
http://world.std.com/~mruelle/multiboot.html
For further details on the commands for the Windows boot.ini file, check out the boot.ini section at www.systeminternals.com
Here are a few more TR articles that might be of interest:
Learn the basics of Linux boot loaders
Feb 11, 2002
Vincent Danen
Transitioning from Windows to Linux
Jun 8, 2001
Lamont Adams
The top five things for Windows admins to learn about Linux
May 8, 2002
Scott Lowe MCSE
Share bookmarks and plug-ins between Linux and Windows clients
Feb 25, 2002
Rodrigo Zamora
I have had the best luck searching the TR archives when I use all lower case letters.
For general information on Linux, sign up for the Linux Tech-Mail.
Also, sign up for the Text version Linux daily e-mail from www.emazing.com
Both will give you some good tips and links.
Chas