I have found getting involved is the best way to see how contributions are used. Have you considered joining a local civic organization that provides community services besides being a local bar for members only.
I found VFW has some chartiable functions in addition to their more primary function as a social gathering place similar to a local bar. Lyons and shriners have specific goals for childeren's hospitals and community support. Forresters and Rotary International seem to be solid with local community support along with Kiawanas who are big on getting the youth involved such as Little League.
I support Guide Dogs for the Blind and take an active part in their annual fundraiser and am a puppy raiser, a worthwhile volunteer project if you can commit the time nessarry to do it corrrectly.
Best advice is to see who porvides what services and what you want to support. Youth spots, emergency services, senior services, veteran's social services,childeren's hospitals, childeren's eyeglasses and hearing aids, whatever. There are lots of non profits. Some are more a business such as the Girl Scouts.than we care for. I had become good friends with a guy who's job it was to produce cookies for the scouts and was shocked at how much the wholesale cost is for the cookies. The scouts only get a very small portion of the sale price. Most goes to the supplier of the promotional material.