Is it hard work to maintain all your blog? Or it's just that you want everyone to post their article in your blog, maybe to create a community, etc. Whatever the reason is, this tutorial will show you how to allow ALL (yes, you heard me right, ALL) people, not just predefined folks, to post in your blog, while retaining your authority to moderate them.
Ok, so our no. 1 step is to go to Dashboard > Setting, and choose the 'Email' tab. There you can see the 'Mail-to-Blogger feature. It's usually yourusername.(blank)@blogger.com. Now, fill in the blank with whatever word that suits you; that email address will be used by everyone to mail their post to. So if your username is Jack and you fill the blank with 'posting', any email sent to firstname.lastname@example.org will be automatically posted in your blog. After you fill the blank, hit Save.
The next step you should do is to tell everyone you email address (the one with @blogger.com) so that they can mail their post. You can do this via the Text gadget (read this for more detail http://blogger-newbies.blogspot.com/2008/12/adding-text-to-sidebar.html) or a welcome note, whatever you see fit.
If you want to see the official Blogger tutorial, see this http://help.blogger.com/bin/answer.py?hl=en&answer=41452