1. turn on Windows File Sharing in the Sharing preference pane
2. click the Network icon in your Finder sidebar
3. browse through to the PC's workgroup
depending on how things are setup already, you might have to fiddle with the IP addresses before they talk to each other, ie: give the Mac 192.168.0.1 and the PC 192.168.0.2
as for the printer, i've never managed to do this successfully. i've added the PC printer on my Mac, but it only ever printed out a mess of jargony-gobbledegook*. haven't tried in a while, though, so it might work better in 10.3.8
*technical term