I would suggest making a check list of What exactly you are looking for.
For example, Guild progression, RBGs Guilds/groups, Population, Also if you spend any time in org might want create a level 1 and see if you can stand trade chat, Also another thought to Consider is Languages If you are say french perhaps you would like to raid in a french speaking guild.
I would start with Population then Lower the server choice down dependent on your other choices, I would suggest staying away from a guild that is almost full, almost full in my experience is bad, a nice medium pop server Is a nice place to be
US|Thrall|Horde Yea, I Love Plate
Ike(Fury Warrior) Oit(Dk Tank) Oiz(Holy Pally)