Egosoft guides (patch notes are here)
Rebirth v1.25: features video.
Rebirth v1.30: Upkeep Missions video.
Rebirth v2.00 can guide is here.
Rebirth v2.50 Diplomatic Aid missions are explained in this video.
Rebirth A v3.00 feature guide is here.
Rebireth v3.50 Flight Assist OFF guide is here.
Player guides
Boarding by XenonSurf (link).
Barding trick with Traitor drones ("XenonSparky Maneuver") by Sparky Sparkycorp and XenonSmurf (link).
http://forum.egosoft.com/viewtopic.php?p=4543757#4543757
Crafting by Tamina (link).
Hidden containers by Snafu_X3 (link).
Hidden ships by euclid (link).
Keyboard Command / Hotkey List by Ameer Nuub (link).
NPC Small Talk & Trade Agents by Sparky Sparycorp (link).
NPCs for hire by euclid (link).