I found this article an interesting read. It's nothing new to the folks around here. But it's thoughtfully written, with thoughtful comments below.

http://artofmanliness.com/2012/02/01/disaster-relief-how-to-get-hands-on-and-volunteer/

It is indeed a fine article, but it emphasizes responding to large scale disasters. There is another way to contribute- involvement with your local SAR outfit. You will be contributing, without having to divert massive amounts of time and money from such trivia as career and family.

I offer this as a long time SAR volunteer, who can now look back on the work I did, realizing the enormous benefits it gave me - the ability to productive engage in substantive teamwork, heightened ability to improvise, adjust, and work toward a common goal, and lasting, deep friendships, as well as the development of a certain amount of survival and emergency medical skills (now rather rusty), are just some of the benefits. I found that the more I contributed, the more I received. The point about local involvement was that I was able to do this while maintaining a career; situations vary, and not everyone can do this, but usually something can be arranged. It is a lot easier to skip out of the office two hours early that to fly off to Haiti for a month.

Organizations vary, as well, and not all are likely to be worthwhile, but I would recommend looking into the local choices. I'll bet you will be glad you did.

Amateur radio (ARES and/or RACES) or the American Red Cross are two great places to get started. Most Red Cross chapters actively respond to house fires where the residents need assistance, so their volunteers get experience year-round. A lot of amateur radio groups help provide communications for events like fundraising walks/rides, parades, etc. which helps volunteers learn to communicate effectively during chaos. CERT is another great organization to get involved in but it really is just for your local community.

I don't think any of the larger organizations would ever send a "green" volunteer overseas to a disaster. There are plenty of para-church organizations that would, especially if you can pay for your transportation.