There are almost innumerable worthy charitable causes out there and you probably want to help a good number of them. For reasons of both time and money, however, you may find that you need to narrow down the organizations that you regularly support. You may have already identified your subset, but if you are still evolving your giving strategy, it is a good time to try on various charities for size.
Joining and/or supporting multiple organizations at a lower level for a year or two will give you the opportunity to interact with the organization, receive its newsletters and annual reports, and generally get a sense of how you and the charity get along. When you find the groups that both promote the causes you support and do so in a way that is comfortable for you, you can feel better about committing more of your time, money and advocacy to those causes.