For Mac Users:

Open iCal. Create a new calendar and events or select an existing calendar.

From the menu select "Calendar -> Publish...".

In the Publish window enter "http://mather.harvard.edu/calendars" into the Base URL box. Additionally, select a unique name as your "Publish" name. If two tutors select the same name, they will overwrite each others' calendars.

For PC Users:

Download and install Mozilla Sunbird from http://www.mozilla.org/projects/calendar/sunbird_download.html
Add your events to a calendar.

Then when you want to publish them, you select the events, goto "Tools" -> "Publish Selected Events".

Then for the "Publishing URL" enter "http://mather.harvard.edu/<yourname>.ics". <yourname> has to be a unique name, otherwise you risk overwriting someone else's calendar.

To make this your default publishing URL go to "Tools -> Options -> Publishing" and setting the "Default Remote Filename" to the "http://mather.harvard.edu/calendars/<yourname>.ics".