I wanted to call attention to the Community Hacks Chris_Stallone creates in the The Water Cooler community. There's a lot of great info here on getting the most out of using the communities! Check these out below:
Community Hack: Tech Tips
Community Hack: What You May Have Missed
Community Hacks: View Only Unread Notifications
Community Hacks: Communities Go Mobile
Community Hacks: Navigating Gamification
Community Hacks: Endorsing Skills and Expertise
Community Hacks: Bookmarks
Community Hacks: How to Make Files AutoPreview
Community Hacks: Installing Apps
Community Hacks: Recovering Lost Posts
Community Hacks: Advanced Editor When Replying
Community Hacks: Managing Privacy Options
Community Hack: Hide Notifications
Community Hacks: Stopping CA Communities Update Emails