At last we have a book available that gives tips and advice on facilitation of end of iteration retrospectives. Esther Derby and Diana Larsen have just published Agile Retrospectives: Making Good Teams Great. The book will be really useful to agile coaches and team leads who want to apply retrospectices in their teams. Plenty of exercises are described so that your retrospectives won't get boring and will continue to reveal process improvements that help your team optimize their process and stay sharp. This will become a well-thumbed trusty reference for agile teams.