The primary source for Eberron canon are the sourcebooks released by Wizards of the Coast. The sourcebooks contain all the game mechanics information on Eberron, as well as ways to incorporate other Dungeons & Dragons published content into the Eberron world.

Eberron Player's Guide (book)

Eberron Campaign Setting (book)

Races of Eberron (book)

Secrets of Xen'drik (book)

Sharn City of Towers (book)

Dragonmarked (book)

An Adventurer's Guide To Eberron

Player's Guide to Eberron (book)