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).
Crafting by Tamina (link).
Hidden containers by Snafu_X3 (link). http://forum.egosoft.com/viewtopic.php?t=381745
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).