The users that are shared to you will now be available in your users tab and you will see if they are online and information regarding from which server they are shared. If a user group has been shared, any new user that is added to the shared group will instantly be available on the server to with which the group is shared.
Users can only be shared one level, which means that a guest user cannot be further shared from the server on which it resides as a Guest user. As mentioned earlier, having one group for each database you share users to make administration very easy. You simply add a new user to the group and it will be shared automatically.
If a share is disconnected for two weeks then shared users will get the status Locked for use. Reconnecting the share or making the user a home user will unlock the account.