Best for what? - Validating early ideas: The Mom Test by Rob Fitzpatrick - Very early sales (not a book, but): https://stripe.com/en-us/guides/atlas/starting-

Best for what? - Validating early ideas: The Mom Test by Rob Fitzpatrick - Very early sales (not a book, but): https://stripe.com/en-us/guides/atlas/starting-sales https://stripe.com/en-us/guides/atlas/starting-sales - Interviewing potential and current customers: Deploy Empathy by Michele Hansen - Marketing ideas: Traction by Gabriel Weinberg and Justin Mares - Deeper marketing ideas: Forget the funnel by Claire Suellentrop and Georgiana Laudi