These are the blogs I read daily. I recommend you check them out.

General
WoW Insider – Premier Warcraft News Site
Dual Boxing

Classes
World of Matticus – Priest Blog (among other things)
Tank Spot
Blessing of Kings – Paladin Blog
Greedy Goblin
WoW Economist
I Tank Stuff
WoW Friends
BrigWyn – Hunter Blog

Armory Scanners
WoW Achievements – Achievement leader board