Some books on my reading list (or were at one time):
Facilitator's Guide to Participatory Decision Making by Sam Kaner (0865713472 or 0787982660 2nd edition)
The Fifth Discipline: The Art & Practice of The Learning Organization by Peter Senge (0385517254)
Project Retrospectives: A Handbook for Team Reviews by Norman L. Kerth (0932633447) is the standard reference for retrospectives.
Expert One-on-One J2EE Development without EJB by Rod Johnson (0764558315) looks interesting.
Mentoring by Chungliang Al Huang and Jerry Lynch. [http://bossavit.com/blog/incip-cmts.cgi?entry_id=829 Recommended] with reference to Ron Jeffries' blog.
Refactoring to Patterns (0321213351) by Joshua Kerievsky. I've read some pre-publication excerpts from this book. It's a good addition to Martin Fowler's Refactoring book.
Object Oriented Reengineering Patterns (1558606394) by Serge Deymeyer, Stephane Ducasse, Oscar Nierstrasz. Recommended by Michael Feathers:
Sometimes external design reviews devolve into audits.. that whole checklist thing. It happens because it is easier than really going in and groking the design. Successful external reviews target the macro and micro design levels. In a trusting atmosphere you can ask where the code the team is most proud of is, and where the areas of uncertainty are.
One good book that helps for external reviews... (on ExtremeProgramming@yahoogroups mailing list)
Test Driven Development: By Example (0321146530) by Kent Beck. A step-by-step demonstration of Test Driven Development (TDD). Some will complain about the amount of detail in this book, but if you don't have an experienced TDDer sitting next to you, that detail may be just the ticket.
Test Driven Development: A Practical Guide (0131016490) by David Astels is another good option for learning TDD.
Software for Use: A Practical Guide to the Models and Methods of Usage Centered Design by Larry L. Constantine, Lucy A.D. Lockwood (0201924781) I've learned a lot and user interface design from [http://www.foruse.com/articles/ Larry Constantine's articles], and from attending his session at the Software Development Conference. I think this book would tie it all together.