Short Summary

You don't have time to read everything. I get that! But I already eliminated repetition from those pages, it's just a huge topic.

Anyway, the CliffsNotes version:

It's nice if a start can be interesting. You can even ignore the principles of good writing to create an interesting start. Those hyper-interesting/goofy starts, designed to sell the book, are often spoilers, they often distort temporal flow, and they have other problems, such as distorting focus or even being wrong.

Also in the sell-this-book department, you can also take a great scene from your book and make it a prologue. Without context it will be less interesting, and almost certainly a spoiler.

Otherwise, the natural start is description (context), but the more difficult (for the author) and probably more interesting start is action. Context can then be implied or mixed in. Because mystery is considered a good hook, it has to be okay for a little mystery to occur before context is filled in.

It's nice to start with the precipitating event. Other possibility is life-as-normal, primarily when you want context for the precipitating event. Wherever you start in the timeline, you throw the events before that into the past, usually complicating their presentation but sometimes to good effect.