I often put all my loose change in the Help For Heros charity box in Starbucks. Besides that, I try to support Animal rescue centres as much as possible. I donate all my used books to a PETA book sale that takes place monthly in this part of Spain.
It's difficult to decide one particular charity to give to. I would like to help people with disabilities but there a other worthy ones too. Can't commit myself to a certain amount each month but I give what I can when I can. Just by giving stuff to a charity shop or buying from a charity shop or sale helps too.
Having had 3 easy births I give to http://www.endfistula.org/q_a.htm
These women go thro' hell.
I also give to our local hospice because they are wonderful.