The web itself offers many opportunities for developing your skills through exploration and self instruction. See the Yenza! page on web development resources for additional related links.

Hotwired's Webmonkey
This site contains a wealth of information and tutorials from basic to bleeding edge. Webmonkey also has an e-mail information service which lets you know when material is added to the site. The Webmonkey front door is located at http://www.webmonkey.com/

The Webmonkey Teaching Tool provides mini-tutorials on HTML basics, including self-tests for each topic.
http://hotwired.lycos.com/webmonkey/teachingtool/index.html

Useful self-instructional tutorials on developing web pages with Netscape Composer are available from California State University http://www.csulb.edu/~jvancamp/composer.html and Xavier University of Louisiana:
http://www.xula.edu/Administrative/cat/workshops/
composer/index.html

Bruce Lane's online guide to developing basic web pages with FrontPage Express can be found at:
http://www.stemnet.nf.ca/~blane/writing.htm

Weaving Your Web Site (Canada Computes)
This site offers a series of articles on web development topics, from the basics of web development to more advanced topics.
http://www.canadacomputes.com/v3/section/
view/1,1297,283,00.html?tag=134&sb=283

Web Design for Librarians (Rutgers University)
The title says it all! This site offers annotated links to web development resources with a strong focus on information design and usability:
http://scc01.rutgers.edu/SCCHome/policies/web.htm

Providing Information on the World Wide Web (Library of Congress)
Links categorized into general resources and guides, URLs and addressing, HTML, web server software, Java, Javascript, and ActiveX, and web statistics:
http://lcweb.loc.gov/global/internet/dev.html

WWW Information Pack 
This set of resources from the University of Aberdeen includes a section on authoring for the Web: 
http://www.abdn.ac.uk/diss/webpack/