I read The Manager's Path and I was not impressed. She has one chapter on mentoring and the advice is very vague and hard to put into action.

Sources I would recommend:

Peopleware: Productive Projects and Teams Tom DeMarco and Tim Lister

The Mythical Man-Month: Essays on Software Engineering Fred Brooks

Software Craftsmanship: The New Imperative Pete McBreen. Includes several sections on managing and mentoring software developers from apprentice through journeyman to mastery