For those that are just getting into website design and development, there are two types of sitemaps and both still work great. The old school sitemap is a html listing of your most important web pages (url’s) while the new xml sitemaps not only list your urls, but give each one a priority of important from .01 to 1.
These priorities are set by you and are only suggestions to search engines; search engines will decide for themselves what’s important and what’s not. Many state that the priority is not taken into account by the search engines and it’s the way you link to your own pages that determine the importance. I believe the main purpose of the sitemap building, both the html and xml sitemap, is to help search engines find your internal pages.
In fact, if a search engine can’t find one of your internal pages, then you seriously need to examine your code. Search engines do a great job at finding all your links, some even follow javascript, so when your page is not listed in the search results, you’re doing something wrong. Perhaps you have duplicate titles or descriptions, perhaps the server is producing an error you’re not aware of, but being seen by the bots.
The best way to find out why you are not being indexed is to crawl your site as a search engine bot would. AuditMyPC’s free sitemap generator (http://www.auditmypc.com/free-sitemap-generator.asp) will show you a graphical representation of your site including server errors, server headers (the way your site responds to computers requesting information), duplicate titles, descriptions and does sitemap building (both html and xml) for all search engines. If you don’t spot it yourself, then leave a comment explaining your problem and what you have don’t to fix it to get free support.
No matter what you have running, be it a content management system or custom code, you need to make sure your site is error free BEFORE you submit your sitemap; you want that initial crawl from the search engines to grab correct data or it could take up to six months to correct the mistakes depending on site popularity.
I initially mentioned that some sitemap building software can harm your rankings and decided to create a separate page for this with instructions on how to discover such deception. Should I find such software during my reviews, I will clearly alert you of such on the associated page.