The Three-state workflow is an out-of-the box workflow tool available in SharePoint 2010. You can use it for either lists or libraries. However, the list or library must have at least one field that is a Choice field. If you have several, you’ll have the option to choose which one to use as you create your workflow. From either the List or Library tab, click the Workflow Settings button and choose Add a Workflow. Choose the Three-state option.
After completing the basic information, click Next. This is where you’ll choose the field you wish to use for your state or status.