Threemacs.com - great networking page 
How to download mac files on a PeeCee. (PDF)
Backup options for older Macs.
Transfering files between older Macs and newer Macs.  
Networking 2 Macs with a Printer cable
Quick file sharing setup guide
 Surf the web through another Mac - Mac Plus or up
I set up two Macs: (Plus and Color Classic) as web servers at the same time.
Quick File Sharing Setup Guide
Timhiggins.com has some great info on sharing internet connections and networking of all kinds.
Using a classic Mac as a file server
Networking Macs
Networking Mac to Mac or PC to Mac with two modems
Mac 512 Network Software From The Mac 512 UG
Sharing any printer on a Mac network (even if the printer doesn't support sharing)
More info on networking Macs.
Download a tutorial on netowrking (HTML format)
AppleTalk ZOnes tutorial