Hi all, I need your help. I've just created sitemap.xml using free online sitemap generator. Everyday I make new postings to my website. My question is: Will I have to my sitemap.xml regenerated and resubmit it to google webmaster tool?

Your info is highly appreciated.

Google Webmaster tools will remember your sitemap and will re-download it every so often, You can go to Google Webmaster tools and resubmit if you like, but Google remember where it is, just update the sitemap.xml on your server.