Blogger users who wanted to submit a sitemap to Google Webmaster Tools have always had some disadvantages. Since we can't publish a real sitemap to the domain we are using we had to settle for only submitting a partial sitemap by using our default site feeds (which only contain the last 25 posts). Add to that confusion when Blogger introduced Feed Redirection (to FeedBurner or others) made things even trickier, as for awhile if you chose the feed redirection option, then you couldn't submit a sitemap. Fortunately Blogger came up with a super secret option (so secret they never bothered to tell anyone) that fixes the problem for submitting a sitemap when feed direction is enabled ( hat tip to Amit for letting their secret out). And in the same step opened up a way to submit all your posts in a sitemap, instead of just the last 25.....

So, starting at the beginning. To submit a Blogspot hosted blogs feed as a sitemap to GWT, you have to use the root-level feed that Blogger provides.

http://yourblog.blogspot.com/atom.xml
http://yourblog.blogspot.com/rss.xml

Of course change yourblog to your blog name, or using your custom domain. Which one you choose doesn't matter really, one is Atom and one is RSS format. Either will work.