1. Get inspired. Keep bookmarks of interesting beautiful designs you like. Think about what makes it beautiful. Similarly, think about why you don't like any particular design. How it can be improved.

2. Learn. Learn both practical things like HTML5, CSS3, Graphics Design for web(icon/logo etc) and theoretical things like color theory, grid system, UX design, etc. Read books, blogs, html/css code for it.

3. Practice. Use what you have learned to design some sites. You can design your own sites, templates, or redesign some existing site you like.

4. Share your work with other people and get their feedback. Make improvements based on their suggestions.

5. Rinse and Repeat. Be patient. Like all arts, designing improves with time and effort put in.

Some resources you may like to use -

http://www.awwwards.com/

http://www.smashingmagazine.com

http://www.cssmania.com/

http://dribbble.com/

http://www.uiparade.com/

http://patterntap.com/

http://ui-patterns.com/

http://developer.yahoo.com/ypatterns/

http://www.welie.com/patterns/

http://www.alistapart.com/

http://siteinspire.com/

http://designingwebinterfaces.com/explore

http://www.reddit.com/r/webdesign

http://forrst.com

http://paulstamatiou.com/startup-web-design-ux-crash-course

http://www.slideshare.net/Wolfr/design-for-developersonlinev...

http://52weeksofux.com/