Osamuko – the greatest english Reach Mahjong blog out there. must reading for everyone.
ReachMahjong.com – the website of Jenn, Garthe (the American JPML Pros) and Gemma (EMA Pro). They have news, podcasts, and more!
Beginners’ Luck – a great basic-to-intermediate website for mahjong theory. Google Translate works rather well on it, so take a look!