This is one of those books that was helpful for me 18 or so years ago, that I have only picked up once or twice since (to read), but which I keep on my office bookshelf as a resource for clients. The central concept is that we have an inner child who needs certain things, and we can help meet those needs for the inner child, which will help us be more balanced and whole. I have found other systems for dealing with the past that are more helpful for me, particularly the work of C. Terry Warner (Bonds that Make Us Free) and Ed Smith (Healing Life's Hurts). A good reference book, or a good foundational book for someone who is looking for ways to deal with the past.
Recommended by my Mom, who has done more for my professional development than any other person, except perhaps my wife.