Better Preview provides you a preview button for the article you are working on. See what the article will look like before saving or publishing it!
Advanced View Site
Better Preview also changes the way the 'View site' link in your administrator works. It will make that link go to the frontend equivalent of that page. It will also display links to any parent pages (like parent category pages when editing an article).
How to use it: http://www.nonumber.nl/betterpreview
NoNumber extensions require php 5.3.13+
See for more requirements: http://www.nonumber.nl/betterpreview#requirements