This is where most projects fall down. Defining how the content is to be structured and where it is to go is simply a matter of making decisions and capturing these decisions in the form of a content model that the developers then implement within the CMS. It's not that difficult a task. The problem is when the content has to be gathered to then enter into the site. What happens in most projects is that once the model is defined, the development starts and finishes before any content is gathered. In the case of an existing database, it will be possible to transform the existing content, but often the content model will have additional content that nobody bothers to actually prepare.
This problem usually surfaces when a developer asks for sample content in order to do testing on the system. That's when things grind to a halt as someone has to take the responsibility of actually gathering the content in the right format for entry into the system.
For example, on a recent project...