Where can I find documentation on Unity's event model?

(1A) I am trying to find a document that describes Unity’s event model. Specifically, when do all of the “On” methods get called, for example, does “OnMouseEnter()” trigger before an Update or after.

(1B) I am hoping that the same documentation explains what each “On…” method does. Some are obvious from the name … but I’m not sure what “OnPreCull” does … sounds like garbage collection.

(2) Is there an event handler or script assignment for a scene? Or is this only available with an “OnLevelWasLoaded()” method that is assigned on the camera or some hidden dummy object? What I need is to be able to initialize a series of objects before the scene is “rendered”, because the objects dictate which GameObjects are created.

Thanks, El

These are in the MonoBehavior Documentation