I have used Facebook for several years. This has been a great tool for keeping in contact with so many friends, family, classmates, other educators and parents.
I used Facebook when I was a preschool teacher as a way to post pictures from our day and reminders. I also used this to invite parents to different events we were hosting throughout the year.
I follow Des Moines Moms - this is a group that posts activities and updates for parents. This is great to follow to get information or learn of events in my area. I believe most towns or cities have something similar that I'd suggest connecting with.
I also follow Teachers helping Teachers - this is a group that posts suggestions, ideas, classes to attend, good books to read and even items to sell or places to go that may have items teachers are looking for.