Start with high-confidence christian afterlife books, then narrow by subgenre or adjacent topics.
The Business of Heaven
C. S. Lewis
Heaven, an Unexpected Journey
Jim Woodford, Dr. Thom Gardner
Safe in the Arms of God
John F. MacArthur, John F. MacArthur Jr.
Imagine Heaven
John Burke, Don Piper
What Happens Next
Max Lucado
Heaven Is a World of Love
Jonathan Edwards, Sam Storms
Heaven and Hell
Emanuel Swedenborg
A Divine Revelation of Heaven & Hell
Mary K. Baxter, T. L. Lowery