The Three big Search Engines Google, Yahoo and MSN have improved their services for submitting and monitoring URLs in the last years. The probably better known of both are the Google Webmaster Services. MSN Live has setup a similar but far less comprehensive service called Live Search Webmaster Center, so does Yahoo with its Yahoo Site Explorer. All three services require a login. You can use the Google Service, by registering you Google Account to this Service. To use the Microsoft Service you will need a Windows Live ID and for Yahoo login with your Yahoo Account.
To submit or update your URL you should use the URL Submit/Update Form (no login required). A better way to tell Google about your page/site is to submit a xml-sitemap. You can do so by login into the Google Webmaster Services. If you have authenticated your site by adding a special metatag
<meta name="verify-v1" content="unique_id" />
to the <head> section of your index page, you will be able to upload a sitemap for that site. The unique_id will be generated by Google, depending on your sitename. Alternatively you can upload a special file to the root folder of your webserver. To learn more about Sitemaps Google provides very detailed information. Once you have a sitemap generated and submitted you might need to tell Google that it has changed, when you have added, deleted or modified pages. Some systems like e.g. WordPress, do so automatically if you have the right plugin installed, some do not. So to “ping” Google to refetch your sitemap you can use the following:
www.google.com/webmasters/tools/ping?sitemap=sitemap_url
where sitemap_url is the URL of your sitemap.
MSN Live
The same procedure for submitting / updating information about your URLs and sitemaps apply to MSN Live. You can submit an URL to MSN Live, tell Microsoft to fetch your xml-sitemap and “ping” the service to refetch you sitemap, by using the following:
http://webmaster.live.com/ping.aspx?siteMap=sitemap_url
Where sitemap_url is the URL of your Sitemap. MSN also requires the authentification of your site, you will have to place a special metatag
<meta name="msvalidate.01" content="mail_id" />
to the <head> of your index page, where mail_id is generated from the email adress you registered the page with. Alternatively you can upload a special file to the root folder of your webserver.
Yahoo
Last but no least, also Yahoo provides the possibility to add an URL to Yahoo. You can also register your site with the Yahoo Site Explorer and upload an xml-sitemap. Here too the authentification of your site is required and you can do so by adding
<meta name="y_key" content="unique_id" />
To the <head> section of your index page, where unique_id is generated by Yahoo. If you want to ping Yahoo to fetch your sitemap, use the following format:
http://search.yahooapis.com/SiteExplorerService/V1/ updateNotification?appid=api_id&url=sitemap_url
Where api_id is your Yahoo Developers ID and sitemap_url the URL to your sitemap. Alternatively you can upload a special file to the root folder of your webserver.

