There's a great article about the philanthropy of Myra Kraft (owner of the New England Patriots) in the Boston Globe called Giving Large.
It's long but read the whole thing. It's a great insight into what motivates giving.
Here's a sample:
Kraft treats board work like a job...She says she comes at the work with no agenda other than to ask tough questions; in the one instance in which she felt her questions were not welcome, she resigned from the University of Massachusetts board in 1998 after only four years. “I just raise my hand and ask questions — I think that’s what a person is supposed to do if a person sits on a board of trustees,” she says. “I speak my mind, not to be negative or confrontational, but if I disagree with something, I’ll ask it or state it, and they can throw me off the board. At this point, people know what they’re getting with me.”