I think, in-game manual and knowledge base, would be great.
Sure there are training missions, few help screens with basic flight controls explained, and abundant forum threads with all kind of info (some exact, some misleading) ...
but it would be truly nice to have PAD at hand with interesting stuff to read like which stars are fuel scoopable, or when Federation was formed, or info needed to be searched in order to complete some mission, or explanation what it means when local faction is in lockdown, or how ranking works ...
Kind of PDA that was in Mass Effect, first available with basic knowledge about universe and updated with different data player had discovered during playtime.