I freaking love this game.

Communities:

• CarcassonneCentral.com
• /r/Carcassonne
• BoardGameGeek.com

Strategy writeups:

• https://boardgamegeek.com/thread/264693/carcassonne-road-strategies
• https://boardgames.stackexchange.com/questions/774/what-are-good-standard-strategies-for-carcassonne/
  • how to leave a space where no tile can be laid

Expansions:

• https://www.reddit.com/r/Carcassonne/comments/2ngy2v/what_expansions_do_you_use/