Since version 2.0, we have added support for WP Review WordPress plugin with which you can easily enable the review/rating system for your articles.
Once you install and activate WP Review, go to Settings -> WP Review to setup default plugin settings.
Adding reviews to posts
When you visit your single post edit screen in admin, you will find the options to enter the review data.
Display reviews in post layouts
When you check any of the layouts in Theme Options, you will notice additional option to display Reviews among other metadata we provide (date, author, etc…)
Ordering posts by reviews
Also, inside modules and some other options, you will notice that 3 new options are added for sorting specific posts by review value.