Now that I FINALLY have my G3 working with 10.2, and the router on the LAN sees it, how do I make it accessable by the other machines? I don't know yet how to make the files and folders on the Mac 'shareable'

Thanks.

It's in System Preferences, found by clicking on the apple symbol at the upper left of the screen. Then, click on "Sharing", and check the appropriate boxes. Do this on both machines to make life easiest. After that's done, each machine can be reached from the other via the Finder window.