Dimbal Software has a free XML Sitemap Submitter tool available to you. The tool can be accessed here.
The essence of the tool is that it will automatically “ping” or submit your Sitemap to the major search engines such as Google, Bing, Ask.com and so forth.
A sitemap is an XML based file that lists out the pages and files on your website that you want search engines to know about and crawl. A sitemap provides additional meta data to the search engines so that they can crawl your information more effectively.
For example. You can specify a timeframe for how often a certain page changes. This does not guarantee that Google will crawl that page according to your timeframe, however it does give them a good idea in terms of how often they should try to check it.