Originally Posted by
SilverFlash
Horde has to complete less quests for the achievment(alliance 3423,horde 3260 according to wowwiki).
As for addons,on 3.3.5 your best option would be Everyquest addon+a browser with wowwiki+wowhead+warmane bugtracker open.
Doing a continent one at a time,zone by zone starting from either northern or southern zones,and making notes when a questgiver would send you over to the other continent,so you can pick them up and do them later when you're done with the one you're on.And make sure you do each repeatable quest twice,as most of them counts twice(one on original turn-in,and one for blue turn-in).