'An Introduction to Coping with Low Self-Esteem' offers expert advice to anyone struggling with self-confidence. Includes helpful information on what causes and maintains low self-esteem and proven CBT strategies to beat it.
I'm sure it has lots of good information, but no way someone with poor self esteem is able to apply it in such a way that it will actually be helpful. It might be helpful if it is used by a trained professional to give "homework" besides therapy session, but would be quite overwhelming and too dry for someone to do it by themselves.