For sharing documents to groups:

1. Select the check box next to the document you want to share and click on the Share link present in the toolbar.
2. A dialog box with heading Share Settings will appear on the screen.
3. Enter the groupname of the group you want to share it with
4. Specify the access permission (Read Only/Read-Write/Co-Owner etc.) for the shared document by clicking on the drop down arrow on the right
5. Select the check box "Notify through Email" if you want to notify the group that a document has been shared
6. Click on the Save button
7. An email with the subject "Document Shared to You on Zoho Docs" will be sent to all the members of the group.