The three IPPC AR5 reports published in 2013 (working group 1) and 2014 (WG 2 and 3), and the summary for policy makers (2014) are a good place to start. They are free online and you can pick the chapters that interest you. The Special Report on 1.5 degrees published last year is more up to date, but has more limited coverage of the topics. There are also textbooks at various levels, but the Science changes so rapidly that they are soon out of date.
In Six Degrees, Mark Lynas sketches out what the real, tangible effects of our planet's warming will be, degree by degree — from the loss of coral reefs and mountain glaciers to, ultimately at 6 degrees, the elimination of most life.