The easiest way to set up a network for sharing files and devices is to use the new homegroup feature in Windows 7. Setting up a Homegroup in Windows 7 streamlines the network creation process and provides a simple way to let every PC in the house share files, including music, photos, and movies, and even the household or office printer.

Concerned about privacy?  That’s why HomeGroup is password-protected and puts you in total control. You decide what gets shared—and what stays private. You can also make your files "read only," so other people can look at—but not touch—your stuff.       

The catch? Homegroups only work completely with other Windows 7 PCs. But even if you have only one Windows 7 PC in your home network, set up its Homegroup anyway. Creating a Homegroup will let every user account on that Windows 7 PC share their files more quickly and easily with each other and will let your PC share files with older PCs still running Windows Vista or Windows XP.

For easy step by step instructions follow Youtube video.