What it is: Planbook EDU is a great cloud-based (a.k.a online) lesson plan book.  Because Planbook EDU is hosted in the cloud, all you need is an Internet connection, your plans travel with you.   Planbook EDU is listed in the Google Apps Marketplace and is a natural fit for schools already using Google apps for education (email, calendar, documents, etc.).  The free version of Planbook EDU has nothing to install, let’s teachers access their planbook from any internet connection, is easy to use with word processor like editing, is fully customizable, works in all major web browser and is…