How do I enable file/printer sharing?
Support for file and printer sharing must be turned on before it can be used. The following instructions tell you how to turn it on; visit the file sharing or printer sharing tutorial to find out how to use it.
Windows XP
The easiest way to enable file and printer sharing in Windows XP is to use the Network Setup Wizard. Go to Start » My Network Places, double-click on Network Setup Wizard, and follow the on-screen instructions.
Macintosh OS X
Go to System Preferences (on the Apple menu) and click on Sharing.

The Sharing pane in System Preferences.
Click to check Personal File Sharing. If you want to access your files from Windows PCs, also check Windows Sharing. The “Public” folder in your home folder will be shared automatically. Use the address displayed at the bottom of the Sharing window (underlined in red above) to access this folder from other computers.
Note: Unlike Windows, Mac OS X does not allow you to share any folder you want. Unless you use OS X Server or a third-party utility like SharePoints, you may only share your Public folder.
To enable printer sharing, simply check Printer Sharing in the Sharing window.