Recruiting and hiring executives is difficult for any leader, but especially first-time or early-stage founders who may not have enough knowledge to test candidates for skill in their area of expertise. Thumbtack CEO Marco Zappacosta has been there — and has a roadmap that'll help.

Over the last few weeks, I’ve noticed a number of young men on London’s tube with the same book. The word “POWER” runs down its cover, which is completely red save for a blue streak that perfectly…