Sitemap for your blog

Note: This post is exclusively for blogs based on blogger. Not for others. If you want a post on that please comment below, I would post that for you (for free).


Sitemap are not essential. They basically tell the Search Engine that
  "hey, the content of my site has changed ! Index it again"
But they are not neccessary.
There are many blogs which do not have any sitemaps.
Sitemaps are only supplements. They help Search Engines to be aware of the changes on your website.
Some of the well known blogs don't have an SEO. That's the point. There pages are already indexed.



Why should you have a sitemap:-
1. Your blog/website is new
2. You have links(internal) that or not well connected.
3. You have a large website with too many links.

According to the Google Webmaster Help, blogger automatically creates your sitemap and submits it. So there's no manual requirement.
Your sitemap exists on:-
1. /rss.xml
2. /atom.xml