The standard KVO events beforepropertychange and change are available, as well as one event for each of the observable properties: change:layergroup, change:size, change:target, and change:view. Review the section on KVO in Chapter 2, Key Concepts in OpenLayers if you don't remember how these events work.
In addition to the KVO related events, however, there are quite a few new events that can be triggered from a map object. As with any other event, you can register for these events using the on() and once() methods discussed earlier. We'll group these events into browser events, map events, and render events.