Validators: W3C Validator: this is the official validator from the W3C. Use it to get your HTML syntax compliant to standards. Also use the CSS validator to check your style sheets. You might find the HTML HELP Validator more useful. You can check the hypertext links in your document using the W3C Link Checker.

The Site Valet at HTMLHelp is great. It gives you a variety of tools to bring your HTML pages up to standards of openness and accessibility. Site Valet's also has a Link Checker: this is a useful service is you maintain pages with many links to Web resources. Finds "broken" links.

Bobby: check your Web site for compliance to "the guidelines established by the World Wide Web Consortium's (W3C) Web Access Initiative (WAI) as well as Section 508 guidelines from the Architectural and Transportation Barriers Compliance Board (Access Board) of the U.S. Federal Government."

HTML Tidy: I love this utility! Clean up your HTML and get it up to standards. You can use an online Tidy Service, a TidyGUI for Windows, or see the Tidy Project Page.

Microsoft provides a Design Gallery where you can download small clipart images, photographs, or sounds. This is useful for illustrations.

TransWeb Transparent Gif Service: process GIF images so that they are "transparent" (allow a color to show through to the background).

CWSApps list of Web development tools: worth a look, but beware of tools that generate non-standard HTML.

Check out Evrsoft's free HTML editor, works with Tidy.

Lemmy: This is my HTML development environment of choice. I use it, in conjunction with TidyGUI and file generation techniques, to do my HTML implementation.

Webgenz: Webgenz generates web site documents from reusable templates and content macros. This is Web-building at its best, and provides an alternative to the insanity of WYSIWYG software like FrontPage.