The Best Way to Improve At Chess

I thought I'd throw this question out at chess.com to see what players think, what is the best way to improve at chess?  Now, I've been playing quite a bit (about 10 - 20 games a day.  If I'm not playing here I'm playing offline on my laptop.  Recently, I have noticed that I'm setting up forks quite nicely, I can sometimes tell what will happen three or four moves down the road and I'm not hanging pieces so much but my ranking is still waffling between 1000 and 1050.  If anyone here saw a significant improvement from a book, DVD or program, please let me know.