It is also better to give to a charity with a specific mission, rather than a general cause. For example, it makes better sense to support an organization that provides bone-marrow transplants to leukemia patients than a generic organization fighting cancer (unless you have unlimited funds).
It is also important to start a dialogue with the organization you intend to support. Although this may take work, if you really want to make an impact, it's the only way to go. Before you make a contribution, talk to the charity and learn about their accomplishments and challenges. If you are unable to create this kind of dialogue, then you may want to look elsewhere.
Be focused in your donations. Diversification in giving is not necessarily a good idea. If you've already identified a cause that you are passionate about, you should channel your contributions there. It makes sense to concentrate your giving to a specific cause, it helps the organization of your choice make an impact.
Making a long-term commitment is also in everyone's interests. If you are serious about making a difference, see yourself as a partner with your favorite charity. It is only with a long-term pledge that the organization can bring about a substantive change. Let the organization know they can count on you for a certain period of time.
Here are a few organizations that may be worth your attention.
First, something for children's rights: The Alliance for Children's Rights was founded in 1992 to protect the rights of abused and impoverished children throughout Los Angeles County. The Alliance strives to create a world in which all children are able to have a safe and permanent family, access to quality health care, education and all the support and services they deserve.