Thanks to the ‘heads up’ from Joyce Valenza over at Neverendingsearch about a useful guide for teachers.
Tools for the 21st Century Teacher, is a wonderful little e-guidebook offering a basic introduction to most things social media and discussion about how they may be effectively integrated into instruction. Among the many tools covered are Twitter, Diigo, Prezi, Evernote, Wallwisher, Skype.
Better still, Michael Zimmer at Edutechintegration is working on a 2nd edition with more tools. Free to download and share!