WordPress Testers list provides you the news about latest beta version of WordPress. There are two ways of testing new beta releases, the first and hard way is backing-up your website database then downloading the zip file and then unzipping it and using it on your website via FTP. The easy way is doing the same thing from backend i.e. from admin area dashboard with WordPress Beta Tester plugin.
The plugin provides you a very easy way to get involved with beta testing on your WordPress installation. To start, first install and activate WordPress Beta Tester then visit Dashboard -> Tools -> Beta Testing page and from there you will be able to upgrade your WordPress blog for latest Beta or Release candidate at the click of a button, all from the dashboard.
Once the plugin is activated it automatically updates your WordPress to the latest stable release or bleeding edge nightly so you can test the latest/upcoming version of WordPress, you can select the option from its admin page. But before enabling this plugin don’t forget to backup your database and don’t test it on a live WordPress site.