Six Seconds in Dallas
Last Second in Dallas
JFK: Absolute Proof
No More Silence
Mafia Kingfish: Carlos Marcello and the Assassination of John F. Kennedy
The Plot to Kill the President
Those are all good books, but they're all pro-conspiracy, so a newcomer would get no unfiltered presentation of the pro-WC view. They would also get no exposure to the mortal-error view. The mortal-error view is a minority viewpoint, but it has a number of adherents, and it is based on some hard evidence that refutes the idea that Oswald fired three shots and that one of them hit JFK's head.
Last Second in Dallas is especially important because it contains over 100 pages of material on the crucial new research on the acoustical evidence done by BBN scientists from 2015-2018.