As a Web designer and HTML builder, one of the first places I visit on a Web site is the site map. The site map shows an entire overview of the structure of the site, and more importantly, indicates how much effort was put into usability testing during the site's construction.

According to Jakob Nielsen's Alertbox Usability Study on Site Maps, 27 percent of users turn to site maps when asked to learn about a site's structure. If your site map is poorly designed, you may lose 27 percent of your Web visitors. That could translate into millions of dollars of missed sales for an e-commerce site, or a massive amount of missed leads for a service company.

Here are several ways to build a better, stronger, and more usable site map:

• Lay it all out there: The best site maps have nothing to hide, so include all links, from your privacy policy to your Contact Us page. If it starts to get too long (more than a few page scrolls), consider alternate ways to conserve space like multiple columns or dynamic drop-down boxes.
  
• Separate your content groups: Don't simply throw all of your links onto the page; make each content piece its own headline, with appropriate sub-sections displayed clearly below it. Use bulleted lists and avoid tiny font sizes that are unreadable.
  
• Display the site map link prominently: It's useless to obscure the site map link--place it where it's easy to find.
  
• It's a site map, so that's what you call it: Don't name the link to your site map anything other than Site Map.
  
• Don't get too fancy: Some Webmasters think it's neat to have complicated Flash animated site maps. Site maps aren't meant to be cool--they're supposed to be purely functional, so leave the Flash behind.
  
• Make each link direct: It's frustrating to end up on a Web site page that you don't intend to see. If a visitor clicks on a link, they expect to get to that specific page--not the section overview page.

Examples of excellent site maps

• With a domain name like Usability.gov, it had better be usable! It's actually one of the best site maps.
  
• The Points of Light Foundation's site map is a classic, two-column layout that's easy to read.
  
• CNET's site map contains a ton of links and information--all in a tight, readable package. (CNET is the parent company of Builder.com.)

With a little work and planning, your site map can become a very useful tool for many of your visitors.