We highly recommend this tutorial for developers new to MPS, written by Jetbrains. The tutorial consists of a step-by-step guide which covers the main aspects of writing DSLs using MPS (i.e. structures, editors, generators etc.). The tutorial also has additional information, covering why you should be using MPS in the first place and where else MPS has been used in industry and academia.
If you are not yet comfortable with the basics, this tutorial is another great introduction to language engineering in MPS and will cover the different MPS aspects in a different example DSL.