...your project starts with content, business requirements, then business case and information structure; then branding, workflow, layout, usability, navigation, behavior, "look and feel", wireframes... Sarah and Peter deliver an amazing story to anybody who plays a role in a project. You may own hundreds of books that cover practically every aspect of web design and development. Or, you may get this one. So treat yourself. With every chapter you get more engaged, the examples look familiar, the information is consistent, practical, accurate, realistic, and tremendous fun. It's a web design bible.
Web Style Guide: Basic Design Principles for Creating Web Sites, 3rd Edition