There's no question that Google Now is one of the most critical pieces of software for any Android system. Google is putting a huge amount of resources into the app, and rightfully so, since all signs point to contextually relevant information being a big part of Google's future as a search company.
Android, of course, makes it easy to access any and all of Google's services, and Google Now ties all of that information together into one extremely useful (if a bit creepy) app. Make no mistake: this is the future of search. At least, Google certainly seems to think so, as evidenced by the recent release of Android 4.4 (aka KitKat). Many of the changes that came with KitKat were under-the-hood improvements. The cosmetic changes almost solely came down to a new launcher which basically turns your homescreen into an invisible Google Now. Users can now simply say "Ok Google" directly from the homescreen, and without launching the Google Now app directly, to access voice search, and the full Google Now UI is only a left-swipe away.
Chances are you're pretty familiar with Google Now, but are you using it to its full potential? The guys at TrendBlog have put together a complete list of Google Now voice commands in a handy infographic. You can download the full cheat sheet below, but I'd recommend hitting up the original link, since many users chimed in in the comments section with additional tips.