You should figure out why you want to get better at this game. Make sure the reasons are good reasons, and not because you want to make a lot of money one day....
Well... I guess the reason I wanted to improve was because I believed I could, after having advanced from 400 to 800. Back when I was in the 400s, I just believed that I innately sucked at chess and that there was nothing else to it, but I began trying harder after some higher ranked opponents said that I should believe in myself a little more and that I showed signs of at least some potential. (I had some familiarity with basic tactical concepts like forks and pins, apparently beyond that of other 400s) So after hundreds of games and a few phone help sessions I improved to the 700s-800s, but largely stalled after that.
I'm okay with accepting that I may have hit my limit. Well, okay, I guess it bothers me a little, since people here frequently imply that a sub-1000 indicates low intelligence/lack of effort/etc.
https://www.chess.com/lessons/playing-the-game/the-language-of-chess
https://web.archive.org/web/20140708093415/http://www.chesscafe.com/text/review919.pdf
https://web.archive.org/web/20140708104437/http://www.chesscafe.com/text/logichess.pdf