This blog post from www.teachhub.com has some great ideas for using google and the google apps in the classroom.
This tutorial will show you how to quickly and easily create and share google calendars through your wordpress website.
There are four main steps;
Create a new calendar in google
Share it publicly
Create a bespoke embed code at https://www.google.com/calendar/embedhelper?pli=1
Copy that code in to your wordpress blog post or page.
Watch this video for step by step guidance.
Google have very kindly create a bank of lesson plans and resources to help your students get started with google apps. You can find them here;
Google have an excellent training site that will provide you with everything you need to know about getting started and the more advanced features of google apps.