With some of the bad press that is often given out in regard to charities, it is sometimes hard to know what charity to give to, maybe there is a personal reason to give to one in particular. If you are looking to give it is often perhaps best to follow your heart. However, if you would like some suggestions I have listed a few, just click on the names.
Remember, there is no Christian Law to Tithe, either 10% or anything else. Don't over stretch yourself. As Christians we are in the age of Grace not the Law. So Give rather than obey a tithing order. Just give freely and with a generous heart. God does not need your money either, so when offering money to a church, give rather than tithe. That way you will probably give more than you may expect, as God loves seeing a person's willing generosity.
Apart from those listed below there is also a Christian organisation called Compassion, which allows you to develop a one-on-one relationship with a child in need. You actually choose a child to support and help bring them out of poverty, so you deliver help and see it actioned. It is a rewarding experience, one that is controlled and implemented by local churches around the world. The child learns about God by hearing the Gospel and getting a Christian education. I would certainly recommend checking it out.