Explore a unit, a lesson, or a best practice
This set of iBook format resources is well worth checking out. Just do a search on the iBooks store for "One Best Thing". These materials are free, and produced by educators for educators. Apple describes the "One Best Thing" collection as:
A collection of books, created by Apple Distinguished Educators, that demonstrate the use of Apple technologies to transform teaching and learning. Each "One Best Thing" book shares a unit, a lesson, or a best practice and is designed to help another educator implement a successful practice.