Extend the Admin Post/Edit page

I want to create a plugin that will place a few elements on the post edit page. How do I do this? Is there an action that is run after before the post_edit page is loaded?

Here’s a nice tutorial on how to create custom meta boxes in the dashboard:

http://www.deluxeblogtips.com/2010/04/how-to-create-meta-box-wordpress-post.html