If you only have time for one of these links, I’d start with the interactive 50-State Roadmap. For each state that you click on, a wealth of stats and info are provided regarding that state’s own route to 100% renewables.
The creator of this roadmap was Dr. Mark Jacobson, a professor of civil and environmental engineering at Stanford University, who believes that this goal is well within our reach if we can just muster the social and political will.
Here are two short articles on Dr. Jacobson from:
Just an FYI, Assignment 3, problem 2 for EGRS 352 (Energy Tech and the Modern World) class was on how to reduce CO2 emissions by 50% by 2050 (our own answer with work shown); problem 3 was an explanation on the reasoning.