A new one - recommended to me by @Coach:

Crucial Confrontations Crucial Confrontations

This is an excellent book on the way to confront someone who has disappointed you - setting and maintaining boundaries.

A short "Cliff Notes" version can be downloaded here - also pretty useful:
http://w2.byuh.edu/alumni/chapters/documents/crucial_confrontations.pdf

Me 42, W 39, S8, S6, S2
M 11y, A & ILYBNILWY 11/08
Walking away from a bad situation.

My Sitch

Strength and Compassion
No Resentment