A List Apart - Articles - A Checklist for Content Work | Some good principles here.

In content strategy, there is no playbook of generic strategies you can pick from to assemble a plan for your client or project. Instead, our discipline rests on a series of core principles about what makes content effective—what makes it work, what makes it good. Content may need to have other qualities to work within a particular project, but this list is limited to qualities shared across all sorts of content.