Americans and concerned observers worldwide watched Haiti tremble after a magnitude 7.0 earthquake Tuesday evening, and many immediately asked: How can I help?

Relief organizations largely say that right now, money donations are needed more than additional aid volunteers.

“It’s a bit of a tough one for impromptu volunteers to enter into the fold,” says Richard Muffley, spokesman for the Center for International Disaster Information (CIDI) in Washington. Unsolicited volunteers may not have the needed training from aid organizations and will still need to be fed and housed once in a disaster zone, he says. “Cash is truly the most economical and efficient way of making a contribution.”

But Mr. Muffley and other aid organizations also say there are still opportunities to be hands-on with Haiti earthquake relief – which, they note, will continue long after the shock the quake triggered this week.

How you can volunteer now

For medical workers, the International Medical Corps is still open.

“We are taking applications for volunteer doctors and nurses, but we have a particular need for nurses,” says Crystal Wells, the group’s communications officer in Chicago. Applicants can fill out their information on the "Work with Us" tab of their website. Both medical and non-medical workers can register their offer of services with the CIDI on their website: http://www.cidi.org/default.htm. Aid agencies browse the listings and call on those whose services match their needs.

Muffley adds that hands-on events outside of Haiti, like baked goods and yard sales, can generate much-needed donations.

The Red Cross is not accepting volunteers to travel to Haiti now, but both they and the International Medical Corps say that later, they may need volunteer health-care personnel. “Down the road, [Haiti will need] more medical people, translators, things like that,” says Nadia Pontif of the American Red Cross. She encourages interested volunteers to contact their local Red Cross chapter to get the appropriate disaster training now.

Social-media volunteering

Aid staffers emphasized the role that social media are playing in Haiti relief, to solicit donations, help Haitian families get information about their relatives, and follow the island’s news.

The Red Cross has set up a Family Links database here for relatives to find their Haitian family after the quake. Since yesterday, 14,000 people have registered on the site and more than 1,000 people in Haiti have written to the Red Cross to say that they are alive, says Anna Nelson, a spokeswoman in Geneva.

“Even if [someone who wants to help] doesn’t know any Haitians, they can put this on their Facebook” and let friends know to pass along the database, Ms. Nelson adds.

Ms. Wells of the International Medical Corps says they’re looking for social-media volunteers to monitor their website, which they continuously update to show which donations they need at a given time and who is needed on the ground.

“That’s kind of a different way to volunteer that does make a big impact,” Wells adds.