- excellent sites -

Cherubae's Terranigma Info Page
Contains weapon/item/skill/enemy lists, magirock locations, experience chart, and fan fics.

TerraEarth
Probably the best around for info and media on Soul Blazer, Illusion of Gaia, and Terranigma.

- okay sites -

Terranigma Isle
Has game info, fan fics, secrets, cursors, icons, art, and lots o' pop-up ads.

Terranigma Screen Shots
Has a bunch of screen shots from the game.

Ulan Shad's Terranigma Maps
Has some maps and sprite rips.  Hasn't been updated in a long while.