This, I very much recommend Charity Navigator but also don't obsess over low administrative costs. I've worked with a couple nonprofits and the staff are almost all paid like crap and their enthusiasm to be helping people is absolutely exploited.

Likewise an executive making a $300k salary sounds like a huge a waste, but consider organizations the size of some larger well known nonprofits do actually require a lot of specialized knowledge and skill.

In principle you want to look more at how effective they are. Doesn't help to spent 99 cents of every dollar on aid if it doesn't actually do much good because the staff is paid crap and the executives have no idea what they're doing.