Not every site needs a site map, they can certainly be a good idea. Site maps provide a dual purpose: They provide search engine spiders easy access to all of your site pages and they provide site visitors easy access to all of your site pages. The difference is that search engines and visitors access your site map differently and therefore there are different methods that need to be applied to creating site map(s) that are friendly for both engines and search spiders.

Small sites typically don't need a site map so long as all pages are linked in the main navigation. Once you get into main and sub-navigation menu's then site maps are helpful in allowing search engines and visitors to quickly find anything they are looking for within just a couple of clicks. A single site map can be used for both purposes or multiple site maps can be created. Here we'll address creating site maps for spiders and humans separately.

Site Map For Spiders

.xml file
An .xml document should be added to your site's root directory containing links to all site pages. This .xml file should then be referenced should be compiled and placed into a proper .xml document which should be uploaded into the root directory.

Robots.txt file
With your .xml site map file in place you must then make it accessible to search spiders. Reference the site map in your robots.txt file by adding a line for sitemap: URL (example: sitemap: http://www.polepositionmarketing.com/sitemap.xml)

Keep current
Be sure that your .xml file is updated and uploaded frequently, or at least as often as pages are added or removed from your site. Large sites should implement an automated site map update monthly or even weekly or daily.

Site Map For Visitors

Navigation links
A site map designed for human visitors is just like any other website page. Link to the site map page should be included in the primary navigation or the site’s global footer. Visitors should be able to find this link without too much searching.

Additional page links
Site map should also be linked from various pages within the site such as Help pages and your custom 404-redirect page. This helps point visitors to the site map as a quick and easy means to find what they need.

Overview
It's helpful to provide a short overview paragraph at the top of your site map page. This can be a nice introduction should someone land on this page directly from a search engine or elsewhere.

Heading and layout
The layout of the site map should present a clear visual hierarchal structure or your website. Both headings and sub-headings should be used above properly grouped links.

Text links & descriptions
Site map should primarily use textual links and page should not be cluttered with images or other distractions. It is also a good idea to provide an additional short description (provided there is room) for each link that allows the visitor to better understand where each link will take them.

Keep current
Be sure that your site map is updated and uploaded frequently, or at least as often as pages are added or removed from your site.

As I said above, not every site needs a site map. But those that do should be sure that the site map(s) they create are actually benefiting them. And the best way to do that is to make sure your site maps provide maximum usability for visitors and search engine spiders.