Sven is right, but consider getting a degree in Technology.
Then you'll actually be able to do something.
Sociology is as about as worthless as you can get. Social work is just as bad.
PS College advisers' advice is often free, but accurate? Not very often. HS advisers are worse, far worse.
You saw the social work answers, and, of course, something like that is good general advice. Much will depend on what kind of help you want to offer. A few classes in economics may mean that you can be involved in planning an economic recovery for a poor area. An ecologist can work on methods for development and the feeding of people in need. Imagine what construction and engineering skills might meant to an area with no modern infrastructure. Knowledge of nutrition, transportation, medicine, child care are among the many skills you can pick up in and outside of college, that can help you pursue your career.
If you want detailed and specific answers to your question, talk to someone at one of the various relief agencies such as the Red Cross, UNICEF, etc. They can tell you what skills they need now, and two or four years from now.
I am on leave from work in the corporate sector and thought of having a meaningful break by doing a volunteering work anywhere in the globe and my first motivation was adventure. I am a biology graduate but never practised my being a biologist. Instead, I had my first job with a hotel as a receptionist. As time went by, my career shifted from being a hotelier to being an administrator of one of the drug rehabilitation centres in the Philippines. Now that I am in Pakistan, working as an organisational development adviser for an NGO working in the earthquake-hit areas, I realise that no matter what course you take, as long as you have the heart for helping others - that is more essential. Any course can be beneficial in humanitarian work and that depends on what you really like. If you want project management, then take a course on administration and management, if you want to help doing medical assistance, I bet you know what courses you can take (nursing or you can be a doctor), accountants are also needed in projects, I.T. specialists are very much in demand in UN/WHO/SavetheChildren..etc. , psychologists... try to think HOW YOU WANT TO HELP and take a course related to that.
Well depending on the scope of those you want to benefit, you might want to look into several options. If you want to benefit your local, state, or national community, then you might want to start with a degree in social work with maybe a minor in political science. If, however, you want to do international humanitarian aid like the Peace Core, then it you might find cultural anthropology helpful. However, the Peace Core does not require a specific degree in anthropology because you join them for a short time they could use your help for a variety of task that utilize your expertise. Humanitarian work is also a career, and, like any career, you must know if it fits into your life for next ten years or so without burning you out. I would recommend that your speak to a career counselor to establish your aptitude, likes, dislikes before deciding. You might also want to interview people in such fields and ask them the questions that aren't normally asked, such as how it has affect their personal life like hobbies, families, friends, and relationships. I hope I helped you a bit.
I spent 2 in a financial career before going into the Peace Corp. I quickly discovered that most developing nations need help with the basic infrastructure stuff more than anything.
This means they are actively looking for people to help them develop their water delivery systems, their farming, their technology, their political structure, etc.
I was an English major and had good computer science skills (a self taught programmer). This combination of communication skill and ability to develop software and train folks how to use PCs seemed to be in demand.
However, they were also interested in folks who had studied political sciences and engineering. So it really depends on your own personal preferences and aptitudes.
Good luck, I think you will find this type of career very rewarding no matter which specialty you choose.