Firstly, the general consensus on whether a Google Sitemap is useful is that, yes, it is still unclear. The official line from Google is that this whole program is in Beta, so there are no promises or guarantees. Perhaps by understanding what this file is that we can infer its usefulness.
A Google sitemap is essentially, an XML file that contains information on all the pages on your site. You create this file, send it to Google, and Google will read it. What Google does, from which nobody really knows. You can specify certain p
arameters in the file location (URL) into your web pages, when they were last modified, how frequently pages are updated, and what each side is "priority" is.
Maybe Google is leaving these Sitemap submitted results to a secondary index where they compare the results to their live index. This can let them know how people use (and abuse) program. It is our belief that the vast majority of participants in this program are website designers and marketing people trying to give their customers a Teenie-Weenie leg up on competition in Google. This is not to say that there is no value, though.
It is possible that by telling Google where all of your pages, you can improve your web page saturation in their index. This may indirectly improve your rankings by getting an unlinked or deeply linked page in the index, which was not previously there. But as we mentioned earlier, it is difficult to know if Google is even using Sitemap information in their live index.
So now that you've decided that you want to create and submit a sitemap of your own, you can do:
Firstly, you must create your XML file. Do not bother to do it yourself. There is an excellent free online tool at www.sitemapbuilder.net.
You must now submit the Sitemap to Google. Visit www.google.com / webmasters / sitemaps / login and log in with your Google Account. Do not have one? Do not despair - it's free, too. Once you have logged in, you can add as many Sitemaps as you like.
Do not forget - when you update your site (by adding, removing or moving pages) be sure to repeat this process. You will not need to resubmit your sitemap to Google, though.
Google is also touting their Mobile Sitemap program. This one we believe may be of greater significance. We believe that Google is building an index of mobile-phone friendly websites (Mobile Web Search Beta) and they use these new Mobile Sitemaps as a way to get people to help them seed the initial directory. The mobile Web is in its infancy right now so it would not surprise us if creating a Mobile Sitemap gave mobile sites a significant leg up. But again, no guarantees here - just opinion.
Happy Sitemapping all!
