I don't know if you need alignments per se, 'cause you'll pretty much be either good (for Hero) or evil, with a few people who are neutral. You could include a lawful/neutral/chaotic nature scale in the character profiles however... don't know what good it would do you though...
:edit in response to post below: Make Tiamat Chaotic Good. I guess thats why he got kicked out of the monestary...