I recommend Ronald Morrish's Real Discipline. It is a sane approach, and it is fairly effective.
which of his books would you recommend? And would you recommend the video for a staff training?
I think collaboration is the big one for me, when students are engaged they work more effectively and when they collaborate they tend to be more engaged.
Diana Day's Vision Management
It is best to attend a workshop with her rather than read the book. If your school can afford it, it's better when everyone buys into the same management approach. She did an awesome job in continuing to support the staff at my school after her workshops. She shadowed teachers, offering suggestions and modeling when appropriate. Most importantly, she emphasized the role of the school administrator in supporting the teachers. When classroom interventions did not work, the administrator was required to step in. She shadowed and modeled for my administrator, too. He did a fantastic job following through.