3.5 stars.
It is difficult to judge the advice before trying it out, but it is written clearly, effectively and simply. I enjoyed the approach to spirituality presented here.
A special credit to how disinterested the author was in making this advice seem 'business-like'. I believe the topics of self-betterment and spirituality have seen more than its fair share of hacks and quacks, and Goldberg seems genuinely very far from that world. I implicitly trust the advice given here to be shared in good faith.
What I struggled with (just a little) (as an atheist) was the reliance of religion and religious thinking. Goldberg makes a sincere and excellent effort to make most of this book secular, and while he largely succeed, there is something about spirituality that still requires working with the Divine or its Substitutes (tm). I continue to be on the lookout for a robust alternative.