What is Material Design anyway? Here’s what Google itself describes it as:
We challenged ourselves to create a visual language for our users that synthesizes the classic principles of good design with the innovation and possibility of technology and science. This is material design. This spec is a living document that will be updated as we continue to develop the tenets and specifics of material design.
The spec includes everything you need to know: its goal, principles of the language, and a tonne of resources to get you started.