How to Access Network Preferences from Terminal on Mac

Sharing must be enabled. To see the Mac from your PC's, enable File Sharing (System Preferences/Sharing/File Sharing). You will need to take the additional step of enabling Samba sharing, since PC's don't use Apple's File sharing Protocol (AFP). Do this by then clicking on options, and make sure "Share files and folders using SMB (Windows)" is checked. Turn it on for whichever accounts you wish to authorize.

In order to see PC shares from your Mac, the PC's must be on the same network, with sharing enabled. Share a folder or something. Is it XP, Vista, 7? If it's XP, disable Simple File Sharing. Do so by opening a folder, going to Tools->Options, and find it at the bottom of View. Then right-click a folder, go to Sharing and Security, and enable sharing.

If it still doesn't show up, you may have a network/firewall issue, and it warrants further help.. but try that to get you started.

The network library is intended for client computers bound to a network domain server. A domain server acts as a central repository for configuration information -- mostly user accounts, but also (among other things) mount records. Mount records tell the client computers to automatically mount a certain file server share point automatically. If you use this to tell all the clients to mount a particular share point on /Network/Library, then you can put Preferences, Fonts, etc folders inside that share point and they'll be automatically available on all clients in the network domain.

This used to be a common way to manage network clients in NextStep (the predecessor of OS X), but is very rarely used in OS X. There are better ways to do most thing now, like putting managed preference settings directly in the network domain. At this point, the network library is more of a historical artifact than anything else...