Editing polishes writing into something others want to read. On average it should take as long to edit a post as it does to write it. I am a firm believer in letting posts sit for a day before I give a final edit and publish, you may feel differently. There have been a few posts that I have written, edited and published in all in one sitting. These tend to be the more personal posts, that I am afraid I will lose my nerve to publish if I leave them.