Are you thinking about buying a drone and getting your license to fly commercially (i.e. getting paid). Here are a few good resources I came across during my research and study to become a drone pilot.
FAA- Becoming a Pilot– Everything you need to know to get started.
FAA- B4UFLY App– THE APP to make sure you fly safe and legal.
Drone Pilot Ground School– The study guide I used to pass my test.
Drone Law– Got to know the laws.
The test is not super easy. The test is new and they have a few bad questions that will certainly be removed down the line. Best thing you can do is to study the materials the FAA provides and spend the money for a study guide like Drone Pilot Ground School. Take all of the practice tests you can and walk in with a good solid understanding of the fundamental concepts.