Google Calendar (Below will tell you where to go to try this out.)
Online calendars can be a great way to let students know what is going to happen during the day, week, month, semester—the entire school year! (I was one of those students wondering the what the heck are we doing today or this week.) In today's society, it seems students, parents, and teachers cannot be overly notified of coming assignments and projects. Google calendar can do the trick with helping students, parents, and teachers with this aspect.
With Google Calendar a person can create multiple calendars. As a teacher one could create individual calendars showing class projects, quizzes, tests, reading assignments, etc. Each calendar could be shared with every student in the class. Of course the student would need a Google account or Yahoo account to see these calendars. (I cannot speak for all other calendar and/or email accounts, but it does kind of work with Microsoft Entourage (Apple)/Outlook (PC) software. I will explain below.)
I have created a class Gmail account so that any and everyone can take a look at how it works. Once you have logged in, click on the arrow down box next to My Calendars. From there it will take you to another page. You will notice the calendar titled Dr. Trespalacios EDLT 528 2012. Over to the right click on Shared:Edit settings. This will step will take you to another page and allow you to share this calendar with anyone as long as you have their email address. If you click on the See all event details arrow down box, you can set the settings to what is most appropriate. Most likely as a teacher you will want to leave it to See all event details only.
By entering the emails of say all of your students and/or parents, you do not need to send an email each and every time there is a new event. (Unfortunately, this only works with having an actual Gmail/Google calendar account. It may work with a Yahoo account though.) Once you enter a new event or happening on whatever calendar you are using, instantly everyone else who you have shared this particular calendar with will see this new event. I realize Google calendar may not be the right tool for every teacher, but considering the simplicity and ease of use of it is something to consider.