Google Calendar is a great, free resource from Google. Everyone needs a calendar to stay organized and on schedule. Google calendar is free, easy to use, and accessible from any web browser and is also available on mobile browsers on smartphones. Many smartphones, like Android, iPhone and HP/Palm webOS, automatically sync the device calendar with Google Calendar and there is syncing available for other phones too. It can also sync events with Microsoft Outlook, Apple iCal and Mozilla Sunbird.
You can easily create new events, set up reminders (pop up, SMS, or email), set up repeating events and more. One of the features of Google Calendar that makes it very useful is the ability to share calendars with other people. You can share the calendar with read only access, or grant someone else the ability to edit your calendar too. You can share your classroom or school calendar with others for easy viewing and a team (or family) can share their calendars with each other or even use one calendar.
You can set up your calendar to see other shared calendars on it. For instance, my wife and I share our calendars so we know when the other has an appointment or schedule change. You can even display set calendars, such as US Holidays or team schedules on your calendar. Each will have a different color so you can tell things apart.
It also allows you to send invites for events to others and they can RSVP via email or via Google Calendar.
You can also display your Google Task list on your calendar page and if you set a due date for a task item, that task will show up on your calendar for that day.
Google Calendar is a great resource for anyone looking to stay organized and on schedule and is also great for schools, teachers, and teams to use.