The Open Beta starts on 8th April for PS4 players and on April 13th for Xbox One and PC players. The Beta period ends April 18th. You can read more about the Beta here.
Back to the blog. 2K's blog highlights the essential information for the newcomers. In the blog, you can read about the heroes you are going to play, game modes, progression system, and so on. PC players can also familiarize themselves with the requirements of the game.
For more detailed information head on to the original blog post.