Just follow the quest line and you will get to choose a faction from the linked quest at crumble kingdom leading you
to fort hope where you get to choose a faction.
It does not matter (to me) what faction you go, just go to ordo then tigan and pick what side you like the best (scenery).
The only real diffrence is Pets or faction shop items, one has tiny Yeti other has Tiny ice raptor.
If you wish to change factions at any point then go to the NPC at fort hope and change, how ever it will be a long or short
road to change depending on how much questing you have done for your faction.
Im unsure of the quest givers name in crumble kingdom who Links you to fort hope to choose a faction, im sure its
something like kabodi ? (level 27 quest).
Guide over. =)