I recently came across a great place to start. A guide to marketing written in 1974 that, incredibly, is just as fresh, vibrant and applicable in 2018.
Stephen King is the godfather of modern strategic planning, or ‘account planning’ as it was referred to then. This guide was created to help others in ’70s JWT understand the process of marketing and brand building. The document was typed out and photocopied, and has resurfaced in the last few years.
It’s eerily accurate and still incredibly applicable to the modern problems brands face.