What is the best way to learn chess?

Like all things done well, there's no easy way. :)

Chess can be learnt online very easily and there are a number of available options to choose from online resources. It depends on what are you focusing on, to improve your game or start from basics.

1. Play Chess Online - Free Chess Games at Chess.com

The best website to start learning chess, playing online with  opponents of your level analyze your games with computer analysis feature. This website provides absolutely everything from learning from scratch to becoming a master. Their video tutorials on opening theory, middle game tactics, end game play, pawn structures, piece activity etc provide a good insight on how to maximize your play.

This website will help anybody trying  to learn from basics as well as wanting to improve his/her game.

2. Chess Cube

This website is the 2nd best option to play tournaments online. Here too you can find players of a level equivalent to that of yours and play against them. They have few tutorials and not much of learning from here. Again this website follows and ELO rating system, and this might not be same as your actual ELO.

3. YouTube channels

The following YouTube channels are famous for their analysis on games of various grand masters. World championship matches from the time of Mikhail Tal to Vishy Anand, Candidates matches, Immortals, Famous games etc are all analyses and put up there.

4. Other Misc Links

To learn chess and improve at the game one must have what some refer to as 'The vision' the ability to analyze a position evaluate 2-3 lines to an optimal move limit. By just looking at a position to understand and correctly judge its pros and cons.

This website will do just and teach you how to look at a board How to get to 1900. Here you can find tactics, forks, pins, skewers, end games, openings, every basic lesson of chess.

5. Chess Engines

Chess engines are the super computers that calculate almost any position (until it is bug free) and give you the right moves and wrong, They can analyze your games, Grand Masters games to a good depth ply and give verbose annotations to .pgn files (post game notation). If you can spend a bit or so try Houdini or Fritz 13. I personally use Fritz 13 and find them good for my game analysis. Analysis of own games is very important, study of opening theory, and end games and these engines provide it

For Training with chess experts

Best of luck!