Arnold, Thomas F. 2006. The Renaissance At War. [Washington, D.C.]: Smithsonian Books.
A slim volume at 240 pages and 8×5 inches in size, The Renaissance At War still looks like a promising introduction to the topic. Production quality is high, with numerous reference images and illustrations. This likely isn’t going to be anything wildly in-depth, but should suffice as a usable jumping off point for a general survey of the period. In fact, it would likely work pretty well as a loaner to hand people interested in learning more about the period.
Hale, J. R and Geoffrey Best. 1998. War And Society In Renaissance Europe, 1450-1620. Stroud: Sutton.
Another slimmer 8×5″ volume, War and Society in Renaissance Europe looks to be a much denser, content-heavy work than the previous book. Make no mistake, there are no illustrations or shiny chapter intros here; the focus is solely on the text. This is a boon, as John Rigby Hale was a prolific English historian and author, and his writing reflects both his familiarity with the subject and his academic background. Long, dense sentences and equally dense paragraphs are the norm. Difficult or uncommon vocabulary choices are scattered throughout. Even so, I suspect this will be the first of the two books I go to when it comes time for me to prep for a class on pike and shot warfare.