One of the first coach-training experiences I ever had was Scream Free Parent Coaching with Hal Runkel — and this book remains dog-eared on my shelf. Like other mainstream parenting advise, you have to pull what works for our kids and let go of the rest, but his overall approach to letting go of the little stuff and loosening the reins is great! I particularly like the part about not worrying about a clean room!
His follow up book, ScreamFree Marriage: Calming Down, Growing Up, and Getting Closer, was written with his wife, Jenny, and is another great resource.
Screamfree Parenting: The Revolutionary Approach to Raising Your Kids by Keeping Your Cool by Hal Edward Runkel