The developers Blog will answer a lot of questions on design...

[Percopius]

...and implementation of the sim. Keep scrolling, it's long.

https://childrenofadeadearth.wordpress.com/

[BigBombR]

This should get stickied at the top.

[ImpressiveMediocrity]

This is honestly a godsend for anyone who wants to learn this game, its the closest thing to a module or ship design tutorial you will get.