Remote Web Workspace Login Monitoring

We have a Windows 2003 SMB server with Remote Web Workspace setup and running perfectly.
How do we determine who is presently logged into the server and how do we tell who has been logged in and out in the past.
This becomes important when we have to reboot the server every so often and if folks are not logged out our main sales database tends to be corrupted if the server reboots with the database in use.
We would also like to know who is using this feature.