Search Engine Submisson

Question: My site already appears in the search engines. How often do I need to resubmit the URL(s)?

Answer: If you have inbound links to your web site and avoid spider traps*, you should ideally never have to submit or re-submit your site to search engines. With inbound links, the spiders should find your site, index your content, and return to crawl your page at regular intervals.

However, it is a good practice to develop and schedule a regular internal review process for your web site. If you find that key pages are not listed at all, you will want to manually submit them to the search engines.
Google: http://www.google.com/addurl
Yahoo: http://search.yahoo.com/info/submit.html
MSN: http://search.msn.com/docs/submit.aspx

Additionally, as you continue to tweak and improve pages, you may wish to resubmit individual pages over time to make sure they are spidered and indexed in a timely manner.

*Spider traps are simply anything on your web site that may prevent a search engine from finding or indexing your page. Examples may include frames, complex JavaScript navigation, Flash, dynamic URLs, redirects, or other potential obstacles.