Net Mechanic
This site will check your web site to find broken links, perform HTML validation to make sure the format is compatible with the most common browsers, optimize your images for quicker loading, and monitor your server's performance for speed checking with different modem speeds. NetMechanic is a free online service.

Interactive Tools
This site includes Interactive tools for web masters and site designers. Use these tools to submit and promote your web site or to find problems. Utilities are included, such as an encyclopedia, dictionary, complete reference, and search tools.

How To Build Lame Web Sites
A tongue-in-cheek article describing the methods you can utilize to achieve a poorly designed web sites. Don't follow these methods, and you're site will be fine.

Meta Tags

Meta Tag Analyzer
This will check your meta tags and your HTML code to help you achieve better placement in search engine results. Let their free Meta Tag Analyzer Program check your meta tags and help analyze your HTML syntax online.

Meta Tag Generator
The Meta Tag Generator will automatically generate meta tags used by search engines to index your pages. SiteUp Internet Promotions is proud to offer to the entire Internet community a free download of the Windows 95 Meta Tag Generator.

How to Use Meta Tags Tutorial
A tutorial on using Meta Tags.

References

The World Wide Web Consortium
Find out everything you need to know about the past, present and future of the World Wide Web. This web site has specifications for every web-related language. It's a valuable resource for all web developers.

A Dictionary of HTML Meta Tags

Graphics

Optiview
You can reduce all your graphics using the Gif Wizard Site Scan Monitor, a free service from Optiview.