Several months ago, I picked up a copy of The Reformation by Diarmaid MacCulloch. I have now read it to the end, and think it a remarkable book. Others, far more qualified to make the judgment, say the same.
A great deal of the matter is familiar to anyone who knows European history, but those of us who do not teach it or read it full time will have been vague on many of the details. Here the details are closely and lucidly mapped: Luther's movement from loyal monk to outlawed reformer; Zwingli's and Melanchthon's relations with Luther; the rise of the reformed churches and how "Calvinist" came to be a catch-all term for them; the lead in to the Council of Trent, and the council's consequences; and much more. Probably the most informative for me was MacCulloch's discussion of the Church of England, and how it moved from one dominated by those determined to align with "reform" back to one more aligned with Luther, and eventually to what it has been since. But if you picked up the book to learn the basics about the Anabaptists, the Socinians, the Arminians, the early Jesuits, or St. Francis de Sales, you would get your money's worth.
The Reformation is not a small book. However, the nearly 700 pages are broken into 17 chapters, which in turn have smaller sections, averaging about 12 pages. A reasonably attentive and rested reader can read and comprehend one or two of the smaller sections in an evening. At every other evening, one could read the book in a couple of months, a bit less than it took me.