What and Why submit Sitemaps
The XML Sitemap is the File or the Directorty of your Blog or website of all pages and posts so Search Engines like Google and Bing can crawl your missing pages which were not discovered during regular crawling of search engines.How to Generate sitemap and add to Blogger
This method applied for both regular blogger blogs ex(haccelerator.blogspot.com) for a and also the self-hosted Blogger blogs that use a custom domain (like postsecret.com).
1. First of all Go to this site Sitemap Generator and then type your blogger blog URL or your Self hosted blogger Blog URL
2. Submit your Blog by Clicking the Create Sitemap button and this site will automatically generate a Script for your Sitemap .Copy the entire Text form the Clipboard (see screenshot Below).
3.Next go to your Blogger dashboard and under Settings –> Search Preferences, the enable Custom robots.txt option (available in the Crawling and Indexing section). Paste the clipboard text here and save your changes.
And We Are Done now by submitting a Sitemap Search engines will Crawl all your XML sitemap files via the robots.txt file and you don't have to do Pinging or anything Manually.
TO Add Sitemap to Webmaster Check this post