to complement Wowlaiwai post :
In the combo box select which area you are in 1. is mainland 2. taiwan 3. north america 4. Europe
in the 2nd field enter your realm name, in the 3rd field enter your char name. 4th enter the security code.
Then toy with the options but remember each time you wanna see the result you must re-enter the security code and press the button.
When you log on a realm type "/join english
" to get in touch with the community members.
WoW English/Chinese glossary
(2000+ translated words) found on wow-in-chinese.jfs-web.chEnglish speakers are consolidating on the same realm for Cataclysm check this thread