Manuel Matuzović: Web Accessibility Cookbook
I read this cookbook cover to cover and bookmarked many recipes so I could refer back to them later on when I cook up new websites. With his clear writing and knowledgeable technical skills, Matuzović provides the solid foundation (HTML & CSS) to ensure that accessibility is baked in. If you want to learn web accessibility, this book obviously for you. What not so obvious is how well it teaches HTML and CSS. I definitely recommend it for designers and front-end developers.