TEPCO English info page
The website for TEPCO related issues (nuke plants status, blackouts), here is the official URL in English;
Further, for queries on which specific group people are in, it is recommended that they visit website of each city/ward.
It should be emphasized that people in not damanged areas should refrain from less prioritized usage (in timing and in length) of mobile phones (IN BOTH CALLS AND MAILS). These coopration will provide more capability to anthena stations to process prioritized communication to/from damaged area. (source from NHK community info program in this morning, at 8:15AM, March 16)