The group account service is designed to really easy. No documentation is required to start using it. Please logon www.drivehq.com, go to My Account, click on Group Account, you can easily upgrade to a group account for free.
Once you become a group account, you can click on "Group Admin" link to create/add/edit/delete/disable sub-users. You can create different types of sub-users, create sub-groups or contact groups. You can create folders in your own account and share folders to sub-users.
For folder synchronization, you must use DriveHQ FileManager 4.0 client software. For two-way folder synchronization, you must be a paid account. You can create a folder and share the folder to the other user with full-access right. Then both of you can sync your local folders to the same online folder.