Books I have acquired:
Non-Euclidean Geometry: or, three moons in mathesis by Lillian Rosanoff Lieber (print)
Non-Euclidean Geometry: A Critical and Historical Study of Its Development by Roberto Bonola (online)
Euclid's Window: The Story of Geometry from Parallel Lines to Hyperspace by Leonard Mlodinow (print)
Introduction to Non-Euclidean Geometry by Harold Wolfe (print-library-returned)
The Call of Cthulhu and Other Weird Stories by H P Lovecraft (print- library-returned)
The Universe in Zero Words: The Story of Mathematics as Told Through Equations by Dana Mackenzie (.pdf file of The Geometry of Whales and Ants chapter)
Relevant books I still plan on acquiring:
Geometry, Relativity, and the Fourth Dimension by Rudolf Rucker
The Fourth Dimension and Non-Euclidean Geometry in Modern Art by Linda Dalrymple Henderson
The Inverted World by Christopher Priest
Other sources:
Hyperbolic Geometry by James W. Cannon, William J. Floyd, Richard Kenyon, and Walter R. Parry (.pdf file)
PlanetMath.org
Videos by njwildberger on Youtube, especially the playlist on universal hyperbolic geometry and the non-Euclidean geometry chapter of math history.