It has already been released. You can catch it on saturdays on Nickelodean at 11:00 am.
As of now, there is currently no webcomic for the Legend of Korra. However, Bryke (Bryan and Mike) have in fact implied that they do plan to release webcomics for LoK.
Season 2 of The Legend of Korra was called Book 2: Spirits and the release date was September 13, 2013.
The Legend of Korra - 2012 The Sting 2-6 was released on: USA: 11 October 2013
The Legend of Korra - 2012 Peacekeepers 2-5 was released on: USA: 4 October 2013
The Legend of Korra - 2012 Darkness Falls - 2.13 was released on: USA: 22 November 2013
The Legend of Korra - 2012 Light in the Dark - 2.14 was released on: USA: 22 November 2013
The Legend of Korra - 2012 Endgame 1-12 was released on: USA: 23 June 2012
The Legend of Korra - 2012 Skeletons in the Closet - 1.11 was released on: USA: 23 June 2012
April 14th, 2012 at 11am. (Saturday)
yes after they are done with all the series of the legend of korra
The Legend of Korra - 2012 A Leaf in the Wind 1-2 was released on: USA: 14 April 2012
The Legend of Korra - 2012 The Southern Lights 2-2 was released on: USA: 13 September 2013