The following article contains instructions on how to set permissions to a shared document, for any user, within your SharePoint 2010 site.

1. Open the desired Site Collection or Site. From the left panel select Share Documents.

2. Within the Share Document's List, Select the box next to the document you wish to share.Within the Ribbon, choose Document Permissions.

3. You will now see the Permission Tools. Select the desired permissions you wish to add to you user. Each individual Permission Level is listed and can be changed at any time.

4. Once you have select the desired permission, choose the user you wish to add these permissions to. If the user is not present, you can simple create the user by selecting New then Add user.