I have read almost every major book on the assassination (over 50 in total) but was still rewarded with a number of new facts and insights into these four days. Not only that, the prose is precise, elegant and enjoyable.
If you have a desire for more, especially an equally well-done biography of Oswald, you can go straight to "Reclaiming History" but that book's sheer length and weight may be overdoing it for more casual readers. "Four Days in November" is superb as a stand-alone volume.