One way I like to use Facebook is to join educational groups where I can gain useful tips and ideas to implement throughout the school year. I also like to follow technology groups for different types of apps I use. This allows me to trouble shoot and access new ideas for that app. Here is list of groups that I find useful on Facebook:
http://www.facebook.com/educationhttp://www.facebook.com/pages/ISTE/8828374188http://www.facebook.com/EdchatPLNhttp://www.facebook.com/edutopiahttp://www.facebook.com/pages/Free-Technology-for-Teachers/191553219314?ref=ts&sk=wall