I wanted to enter our kids' school calendars into a calendar program I can access the calendar at work and at home. Also this gives us the ability to have access to the calendars from either of our computers. I decided to enter the calendar into Google Calendar, and it went very smoothly. I noticed one thing that I would love to see in Google Calendar.
Google Calendar can export a calendar to iCal through an ics file. Unfortunately the ics file does not include the alarms for events. This means that iCal, or any devices that sync through iSync, will not alert you for events. Google Calendar has event notification with SMS messages, but these notifications can cost money, as often there is a charge for receiving text messages.