My first suggestion would be to try out Google Calendar. I have used it for my own personal use, and find it quite easy to use and very convenient. It also can be set up to send a daily email digest, or other notifications, to remind you of your schedule.

Another option might be Yahoo! Calendar. I haven't used the Yahoo! Calendar, but I do have experience with Yahoo! groups, and I prefer them over the Google Groups. The calendar feature on Yahoo might provide more features than the Google one, so depending on what you are looking to do, this might better suit your needs.