for sitemap once, even webmaster tool says sitemap has problem (503 etc), I always ignore, it will reclaw next day and everything will ok again.
Never have. No point as Google just picks your site up and crawls it as soon as a good link hits it. If you are referring to submitting a sitemap then do it each time your website is updated with a new page of content.
Only once. Add a site map and Google will come back. But update your site often and generate internal links and deep-links from other sites to increase the chances of Google crawling new pages. Once Google knows your site exists, you only need to make them aware of new content regularly through internal linking and deep-links from outside. Resubmitting will not help you. Imagine Google is just another site visitor. They come to your site and look around, find something interesting and original join an RSS feed. Then you start bombarding them telling them to come back, when there's nothing new there. They already know what's there. Eventually they'll get annoyed and start ignoring you. They might even unsubscribe from your RSS feed because you're just harassing them while offering nothing new. But add content and they'll be alerted. They'll decide if it's original or not. Have they seen it before? Is it just like another update they had from ten other sites an hour ago? That's kind of how it works. Submitting again and again is not the way to do it.
i answer same question on another forum, submit your site once in search engine and Google crawlers automatically crawls the site time by time if you have fresh and unique data for your website in the form of articles and blog posts.
very helpful information about google submissions, but what about the other search engines, directories, etc? thanks, I should be all set now
Besides the top search engines, like Google, Yahoo!, and MSN, I want to submit my website to other search engines. Can I submit my internal pages to Search Engine Submission directories?
You just need to submit your website to Google only once and once your website has been index in Google you dont need to submit it again. And whenever Google change algorithms, it will apply to all website and blog tht have been index in Google server.
I think there is no need to resubmit you site again and again or monthly basis on the Google. When your site is fresh, just submit that, make a xml sitemap, submit and verify that in the Google Webmaster Central. After that you need not to submit your site again a d again, you can just modify your sitemap and resubmit that, if any changes occurs on your site. Just make proper deep linking of your site.
We usually will submit the site map and then work on local directory links while always focusing on good strong content
Are there some rule from google about submit? Cause i use wordpress plugin and they are run automatic and i don't know how many times this plugin will auto submit
Personally I rarely submit, instead I let SE's find my site naturally through links on the web. I use a sitemap to ensure a site is crawled correctly and make sure that the robots.txt file can be accessed to auto discover the sitemap by SE's that support it (mostly the mains ones). I also have a static paginated sitemap page (for some sites) that also links to the XML version.
once is enough however it is better to use auto updated xml site map, i use a auto posting script on my disposable email site