IMHO you first need to understand design, its various sub fields (i.e. typography, colors, layout), user experience design/interaction design/usability, and finally how all of this applies to the web. You can learn the basics by reading books but the only way to truly understand and master is by study this things in the world and by practicing them. Start thinking about design, analyze it in your daily life, do your own makeovers of sites you use, design a blog theme, etc, etc.

As for web typography, you want to check of the latest generation of font embedding because that's where the real magic's at. The most known web font solutions are: CSS3 (font-face), typeface.js, cufon, flir, sifr, Google Font API, Typekit.

Here's a list of quality books on design and typography:

    A History of Graphic Design
    Before & After Page Design
    Designing Brand Identity
    Emotional Design: Why We Love (or Hate) Everyday Things
    Graphic Design Solutions
    How Designers Think
    Information Dashboard Design: The Effective Visual Communication of Data
    Making and Breaking the Grid: A Graphic Design Layout Workshop 
    The Complete Manual of Typography
    The Designer's Guide to Color Combinations
    The Elements of Graphic Design: Space, Unity, Page Architecture, and Type
    The Elements of Typographic Style
    The New Typography
    The Visual Display of Quantitative Information
    Thinking with Type: A Primer for Designers
    Typography Workbook: A Real-World Guide to Using Type in Graphic Design 
	

Books on web design:

    About Face 3: The Essentials of Interaction Design
    Ambient Findability: What We Find Changes Who We Become  
    Bulletproof Web Design
    Cascading Style Sheets: The Definitive Guide
    Designing Web Usability
    Designing With Web Standards
    Designing the Obvious: A Common Sense Approach to Web Application Design
    Designing the User Interface: Strategies for Effective Human-Computer Interaction
    Don't Make Me Think: A Common Sense Approach to Web Usability
    Homepage Usability: 50 Websites Deconstructed
    Information Architecture for the World Wide Web: Designing Large-Scale Web Sites
    Information Architecture: Blueprints for the Web  
    Interaction Design: Beyond Human-Computer Interaction
    Rocket Surgery Made Easy: The Do-It-Yourself Guide to Finding and Fixing Usability Problems
    The Essential Guide to User Interface Design
    The Inmates Are Running the Asylum
    Thoughtful Interaction Design: A Design Perspective on Information Technology
    Web Form Design: Filling in the Blanks