This is a Joker page, ie. it mainly links to things. A possible rework might move common elements from other PGP guides here. For now, feel free to just add links worth reading
Introduction to PGP and PKI by EFF PGP Intro by Carnegie Melon University Key Verification by EFF Operational PGP by the Gurq (not basic) The Zen of PGP by the grugq
GPG Suite by Kyle Thunderbird + Enigmail by EFF
Thunderbird + Enigmail by EFF
Thunderbird + Enigmail by EFF
Open Keychain by pshem
Due to Apple's rules for the App Store being incompatible with the GPL, no ready, open source solution is available. The program below seems to be the only implementation still being worked on. Possible project for dissertation? Objective PGP(program)