I've been making an effort to see the squares instead of the pieces. My best try until now has been to mentally highlight the squares like Chessmaster does, with green for attacking squares and red for defended squares. It isn't easy.
Thinking "squares" rather than "pieces"

Controlling / Identifying weak squares is one of the imbalances mentioned in Silman's system. His system consists of 7 imbalances. Your idea is only one of seven checklist items.
I heard about this before and something about certain openings only have weak / dark/ white squares concept. If you pick up these types of opening, definitely it will be to your advantage of knowing weak / dark squares.
if there's no weak square to attack, what do you do? I think you must rely on the other six imbalances.
Just my $.02 opinion.

I also found this other resource:
http://en.wikibooks.org/wiki/Chess_Strategy/Weak_and_strong_squares

I also found this other resource:
http://en.wikibooks.org/wiki/Chess_Strategy/Weak_and_strong_squares
Thanks u2krazie. The linked article was very helpful. I also found Silman's website and will spend a couple of days looking through it.
Cheers.
Genghis


Thanks estragon for the clarification. It helps a lot. Silman, on his website, defines weak squares as squares that can no longer be protected by a pawn. This may be an "official" definition, but as you point out, weakness is more than that. The squares may be protected by other friendly pieces, giving some reassurance of strength, but when an opposing pawn attacks this weak square, causing a hole, the enemy pawn might as well be kryptonite. No matter how strong the other friendly pieces are, the hole is almost unattainable.
I find this concept a little difficult to put into practice. Looking at the pieces on the board, then at the empty squares, is a little like looking at a photograph and then looking at the negative. (members under the age of thirty may not inderstand that analogy) So I'm struggling in my games a little right now until I can sort this out. But I've no doubt that it will benefit my play in the long run.
There must be articles on the site that deal with this issue. Again, if anyone can point me in the right direction I'd appreciate it.
Merry Christmas.
Genghis

You shouldn't think in squares but you should think in triangles. The squares are merely there to distract you.

Seeing your rating on this site I would suggest attacking manual by aagard. I have only gone over the very first portion of it. But, key squares and how to control them is one of the things which are stressed greatly. He does a great job of explaining whats actually happening in the position.

Ok so I don't know the difference between a hole and an outpost. But they're both weak squares and you can find them so I don't think it's a big deal.
A good example of attacking weak squares was Natalia Pogonina's game vs. chess.com
All annotations are by Pogonina.
[Edit]: The pgn is weird so you'll have to check it out...
http://www.chess.com/article/view/pogonina-vs-chesscom---analysis
Excellent! I took the liberty of E-Mailing NP and asking her if she'd consider writing an article about weak squares, holes, and outposts. She replied within 12 hours! (Isn't it great when GMs are so approachable) and said that she'd certainly think about it if she could get it all together. How she can play tournaments around the world, study chess to the depth needed by GMs, and look after a young family as well, is beyond me. But we're certainly grateful for the time, energy and support the top players give to this website.

Estragon wrote:
"The key is the pawn structure. Think in terms of the pawn structure, and the weak and potentially weak squares will become more evident."
Thanks again Estragon. This reminded me that I had read some articles on pawn structure on the site about 6 months ago. A search produced about 12 pages of articles, and I was also directed to a series of videos by IM Danny Rensch, the first of which is at http://www.chess.com/video/player/pawn-structure-101-introcomplex
Unfortunately the videos are only available with the diamond membership, which being an (ahem) "mature" player I can fortunately afford. I had to stop, start, and replay the video a few times to get all the teaching points, but it was well worth it. With that series on my list, and the pawn structure articles, I have plenty resources to occupy my time over the Christmas holidays.
Merry Christmas everyone
Genghis
I think I've come to a watershed in my understanding of chess.
Until recently I haven't paid much attention to the empty squares on the board. I was too busy concentrating on the pieces. (And that seemed hard enough). But I'm starting to pay much more attention to the non-occupied squares on the board, realising that they too are "weak" or "strong", depending on black or white's point of view.
I get the basics. For example a pawn advance will strengthen the squares diagonally ahead and weaken the ones at the side. But I realise that the concept becomes much more complicated than that, and I sense that the good players pay as much attention to all the empty squares on the chessboard as they do to all the occupied ones. In this way they are able to decide in advance which are the important squares to dominate.
I found one example on the computer workout (weak dark squares - advanced, 1800+) but didn't really understand what I was trying to do and haven't yet managed to beat the computer (although I'm close).
Can someone point me towards resources for further study? And can someone explain the lesson that this example is designed to teach?
Thanks
Genghis