Sitemaps are like a roadmap of your site for searchengines. It is an XML file that contain all the information a search engine needs to crawl your site. Creating one can be problematic but there are a large number of vendors that will provide the service for free.

I use and recommend gsitecrawler.com. Go to their site and download the software and install on your computer. Enter the URL of the site you want to generate a sitemap for and gsitecrawler will follow every link on you site. You also have the option of automatically uploading the sitemap to your site. The sitemap, once generated, is placed in a nominated directory on your computer ready for uploading.

Upload the site map to the top level folder of your site i.e. http://www.yourdomain.com/sitemap.xml and inform the search engines where it is. There are a number of ways to do this. You could add a line to to your robots.txt file like this – sitemap: http://www.yourdomain.com/sitemap.xml
This will inform the search engines where your sitemap is.

Another way is to inform the search engines directly by pinging them.Here are the addresses:

google

http://www.google.com/webmasters/sitemaps/ping?sitemap=http:%3A//www.domain.com/sitemap.xml

yahoo

http://search.yahooapis.com/SiteExplorerService/V1/updateNotification?appid=YahooDemo&url=http://www.domain.com/sitemap.xml

(Replace Domain.come above with the domain of your site)

Another highly recommended way is to sign up to each of the search engines webmaster portals. These are www.google.com/webmasters/tools/, https://siteexplorer.search.yahoo.com/, and http://webmaster.live.com.

Once you start to get your pages indexed in the search engines, your on the way to effective SEO.