Founders' Book is a digital content library that offers a wide range of tools and resources for startups. It includes a collaborative workspace, startup credits for savings on SaaS platforms, pricing information, a startup glossary, product marketing templates, financial model templates, product management templates, SaaS metrics and calculators, guides for building products with no-code tools, daily startup and entrepreneurship updates, a landing page template, resources for launching a product, fundraising questions, startup jargon cards, and more. The subscription-based service provides unlimited access to all content and future updates, saving founders time and money in their startup journey.