Microsoft Knowledge Base Article 301281 contains the following summary:
This step-by-step guide describes the process of sharing folders on a computer that is part of a workgroup,
configuring security for the shared folders and the subfolders and files they contain, and connecting over
the network to shared folders on other computers that are members of the workgroup.
For example, assume that you have been asked to set up file sharing on a Windows-based computer that is part of a workgroup. You need to create a share contains Accounts Receivable files that are to be used by the Accounting and Sales staff at the company you work for, and to configure security to ensure that only appropriate users get access to the data stored in the share. You need the Accounting staff to be able to read, edit, delete, and create files in the share, while the Sales staff should only be able to read files in the share. The manager of the accounting department (Jane Smith) should be the only user who can change permissions on the contents of the share.
The computer you are working with has a drives C and D, and you have decided to create the folder that will contain the data on drive D.