Kołodziej's and Klimek's books are very good, and Demailly's online book also has useful material. You can also try with Zbigniew Błocki's lecture notes
http://gamma.im.uj.edu.pl/~blocki/publ/ln/wykl.pdf
http://gamma.im.uj.edu.pl/~blocki/publ/ln/tln.pdf
This classical paper of Caffarelli-Kohn-Nirenberg-Spruck is also a must!
For the case of compact Kähler manifolds, apart from Błocki's notes above, I would also recommend Siu's book and this Asterisque book in French.

