3 links
Horizons Vault
horizonsvault.ign.com
Member of the Vault Network. Has news, interviews, polls, screenshots, and message boards.
Horizons: Empires of Istaria
istaria.com
Official site, with game information, news, and message board.
Port of Horizons
rpgplanet.com
Game news and information, including a world map, bestiary, forums, guilds, guides, and multimedia.