Common and More in Depth Resources for World Building

Question

What are common and more in depth resources for world building?

SE is a great place to get questions answered but there are other sites and books that allow for a more in depth and broad look at certain topics that are in the vein of world building but may focus on one topic, or the specific topic can't really be put in the form of a question easily.

I think community wikis for the following are a great place to start:
Magic
Planetary Sciences
Civilization
History
Space travel
Stars and star systems
Linguistics Mytholgy, Legend, and Religion

Answer 1

Linguistics

Conlang Making

• Zompist : Home of the Language Contruction Kit

Answer 2

Planetary Sciences

Planet Mapping

• Cartographers Guild : Site to learn how to make a map
• Map to Globe : Turn your equirectangular maps into a sphere

Answer 3

Civilization

Extreme future tech

• Orion's Arm Universe Project: A MASSIVE worldbuilding exercise which has the galaxy ruled by 16 different factions, each of which is dominated by a different ascended technology and explores how to actually build Dyson spheres, matrioshka brains, organic AI, corporate hegemonies, and other galaxy spanning government systems. All the advanced tech imagination you could ever want to explore.