The most important place to find creations by the community is the game’s mod.io page, where you’ll find all games, expansions, and object libraries: https://tabletopplayground.mod.io. You can find guides and useful hints created by the community in two places:
On mod.io: https://tabletopplayground.mod.io/guides
And on Steam: https://steamcommunity.com/app/838410/guides/
If you want to add your own guides, mod.io is the better place: future players who might not use Steam will be able to find your content there, too.