Green Screen removal is a basic skill that every compositor should be able to do. Blender's keying node makes green screen removal as simple as possible. In this two part tutorial series, we go over how to remove a green screen and attain a clean alpha and then the second part goes over footage integration by color grading the footage to better fit the background. Hope this can be helpful to anyone looking to use blender as a compositing program!
Part 1
Part 2