Nickelodeon have said that they may be releasing Book 2: Spirits of the Legend of Korra in February 2013. That may just be the trailers for Book 2 they haven't officially announced full details. Hopefully it will be out soon as we are crrently in March. :)
The season finale of the Legend of Korra, Book Two: Spirits, premiered on November 22, 2013.
The Legend of Korra: Book 2 - Spirits will begin airing on Nickelodeon in the United States in September 2013.
The Legend of Korra - 2012 Skeletons in the Closet - 1.11 was released on: USA: 23 June 2012
Season 2 of The Legend of Korra was called Book 2: Spirits and the release date was September 13, 2013.
Sadly, two years
there is no book 4 however, they are working on Avatar: Legend of Korra
Well as I know and find out is The new seriese the legend of Korra will Have Two (2) books only and the book 1(Air) Have 12 chapters and and book 2 ( don't know what will be about) will have 16 chapters and I don't know if they will change Their Mind or Not cuz the director is pretty creepy first he make his mind to make book 4 but after that he changed agin...,,,, we miss Ang :(
The Legend of Korra - 2012 The Southern Lights 2-2 was released on: USA: 13 September 2013
The Legend of Korra - 2012 Peacekeepers 2-5 was released on: USA: 4 October 2013
The Legend of Korra - 2012 The Sting 2-6 was released on: USA: 11 October 2013
Book 2 is called Spirits, so i think it's more about problems with Korra and spirits. i found some information out about who is going to be in book two, apparently we meet Kya (aang and katara's first child, only waterbender and only girl out of the three of them) and Korra's uncle and his twin daughters
Yes, Mako and Korra will be together in Season 2.