Free Audiobook of the month from christianaudio.com:
John R. W. Stott, Basic Christianity -recommended!
Diagram of Synoptic Relationships (David Pawson)
https://www.davidpawson.com/synopticrelationshipdiagram/Synoptic_Relationships.pdf
https://www.davidpawson.com/synopticrelationshipdiagram/Synoptic_Relationships.pdf