Twitter user @gakuranman put "the radiation levels at Fukushima into perspective" with this handy chart. Meanwhile, Dutch and Flemish broadcasters began leaving Japan due to the threat of radiation, and 50 workers in the Fukushima nuclear plant remained on site to attempt to avert disaster. To repeat--that is 50 workers. Overwhelmed shelters are housing 550,000 people along Japan's east coast after the earthquake and tsunami killed at least 10,000 people. Kyodo news agency reports that authorities have lost contact with a further 30,000 citizens.
If you are searching for someone in Japan, you can go here and enter their details. Google is tracking about 162,000 people through this service. Google also has a crisis response page with shelter locations, message boards and times of expected power blackouts. For a livestream of Japanese television, go here.
Scientific American has an excellent nuclear primer.