Are you interested in the design part of this (e.g. what the page look, feel and functionality should be) or the implementation opf said design? (or both?)
For the former, this SO question (
Learning Design for UI and Website Design
) has many of the answers. (useit.org and Don't Make Me Think and Joel Spolsky design book would be my favorites). Also, see this SO question as well (
Best books to learn about design
).
For the latter, you will need to learn HTML, CSS and JavaScript. Many great resources, but for the basics of JavaScript I would highly recommend to start with "JavaScript: The Good Parts".
Also, for the web site resources, peruse the answers to this SO question (
What are the best web design sites?
)