1st use the launcher and let it install the patch. Then you follow the guide, use the data files from the guide not from any other threads. If you don't use the US client you have to edit enCN.ini as explained on step 4.
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