A content plan is a list of pages you intend to publish. Google publishes a set of questions for judging whether content is helpful and reliable, and calls the goal people-first content: content created primarily for people, not to manipulate search rankings.
The questions are written for content that already exists, but they work as a checklist for a plan, before money and time are spent. This guide shows how to apply them page by page and keep a written record of your answers.