I have a site but I cannot get its URL indexed in search engines like Google, Yahoo, Bing, etc... Please let me know how I can submit my site's URL to Google.
You really don't need to. Crawlers will find you on their own. However, if you would like to help that process a bit then include your domains in Google Webmaster Tools and Bing Webmaster Tools. Both will provide you with a number of "helpful" stats on your site as well.
Also, make sure that you have an XML sitemap on your site. It will assist the crawlers in moving through your website.
Try using http://www.google.com/analytics/, they'll provide a code spinet to insert on the head section of your website.