I'd also recommend by Wienberg: The Secrets of Consulting: A Guide to Giving and Getting Advice Successfully https://www.amazon.com/dp/B004J35LHQ/ https://www.

I'd also recommend by Wienberg: The Secrets of Consulting: A Guide to Giving and Getting Advice Successfully https://www.amazon.com/dp/B004J35LHQ/ https://www.amazon.com/dp/B004J35LHQ/ Originally published in 1986, so has somewhat dated analogies at times, but still really good.