Answer
This question was answered on December 9, 2004.
Much of the information contained herein may have changed since posting.
Is your G3 the blue and white tower, or a G3 iMac? If it's the tower, the right side can be opened and laid down, while machine is up and running. Just don't do anything but look, while it's running.
For cleaning programs, there's Clean Sweep, but I never liked it much. Go to www.versiontracker.com and see what they have for cleanup. You may find other helpful stuff too.
For wireless, Macs use the Airport card and base station. Check the Apple site for info on that. www.apple.com
You might also find the airport stuff at www.macmall.com or do a google search........
Good luck! I believe that once you get the hang of it, you'll end up loving your mac!
By the way.......
Not sure about this, but look around apple's site in the downloads area, and you MIGHT be able to upgrade to OS 9.2 for free.