Put an HTML site map page on your site, and use an XML Sitemap file
A simple site map page with links to all of the pages or the most important pages (if you have hundreds or thousands) on your site can be useful. Creating an XML Sitemap file for your site helps ensure that search engines discover the pages on your site.
- letting your HTML site map page become out of date with broken links
- creating an HTML site map that simply lists pages without organizing them, for example by subject
Have a useful 404 page
Users will occasionally come to a page that doesn’t exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page that kindly guides users back to a working page on your site can greatly improve a user’s experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. Google provides a 404 widget that you can embed in your 404 page to automatically populate it with many useful features. You can also use Google Webmaster Tools to find the sources of URLs causing “not found” errors.
- allowing your 404 pages to be indexed in search engines (make sure that your webserver is configured to give a 404 HTTP status code when non-existent pages are requested)
- providing only a vague message like “Not found”, “404”, or no 404 page at all
- using a design for your 404 pages that isn’t consistent with the rest of your site