From The Washington Post:

Haiti was rocked by a massive earthquake on Jan. 12.

To donate to specific relief efforts in Haiti:
Mercy Corps
Save the Children
International Red Cross
World Vision
UNICEF
International Medical Corps

The State Dept has set up hotline for Americans to inquire after family in Haiti: 888-407-4747

Haitian musician Wyclef Jean is asking people on Twitter to donate to his organization Yele Haiti:

@wyclef: Haiti is in need of immediate AID please text Yele to 510 510 and donate $5 toward earthquake relief.

You can also find updated information and general ways to help during disasters at ReliefWeb and USAID.

For a photo gallery of the damage done in Haiti, go here.