Cheats and Hints

Cheat Code Central
Contains codes and hints.
http://www.cheatcc.com/psx2/dc.html

Game Revolution
Includes codes, hints, and lists.
http://www.gamerevolution.com/oldsite/games/codes/ps2/dark_cloud.htm

GameFAQs
Includes guides, walkthroughs, and message board.
http://www.gamefaqs.com/console/ps2/game/197042.html

GamePro
Contains cheats.
http://www.gamepro.com/sony/ps2/games/cheats/14421.shtml