The Principles of Beautiful Web Design: Designing Great Web Sites is Not Rocket Science!
The Principles of Beautiful Web Design is the ideal book for people who can build websites, but are seeking the skills and knowledge to visually enhance their sites.

This book will teach you how to:

Understand what makes "good design," from discovery through to implementation
Use color effectively, develop color schemes, and create a palette
Create pleasing layouts using grids, the rule of thirds, and symmetry
Employ textures: lines, points, shapes, volumes, and depth
Apply typography to make ordinary designs look great
Choose, edit, and position effective imagery

And lots more...

This easy-to-follow guide is illustrated with beautiful, full-color examples, and will lead you through the process of creating great designs from start to finish.
The third edition of this book has been greatly revised and now features:

Updated and expanded coverage of mobile and responsive web design (RWD)
A new sample project
New sections on user interface and icon design
Common user-interface patterns and resources