Hi there! This question relies heavily on whether or not you can read Spanish. There are unfortunately very few books on the war in English.

Only three general books on the war has ever been published in English: The War Between Peru and Chile, 1879-1882 by Sir Clements R. Markham (published in 1882 before the end of the war), The Ten Cents War: Chile, Peru, and Bolivia in the War of the Pacific, 1879-1884 by Bruce W. Farcau (2000) and Andean Tragedy: Fighting the War of the Pacific, 1879-1884 by William F. Sater (2006).

If you want my personal recommendation, then Sater is the best. He's perhaps the greatest Chilean history expert we have in the west.