Question: In chess books and magazines I read about weakness on the dark squares or light squares. What do they mean by these weaknesses? And why does it matter?
Q+A for beginners(and everyone else)

In some middle game position, I can't find a good move. Is my startegy of playing a "waiting move" acceptable? I simply move my king.

This isn't a beginner question. Which would you prefer to play as black? Ruy Lopez Marshall Gambit or Benko Gambit and why?

Why are beginners shy? Which system or opening benefits beginners most? Colle System, Kings Indian Attack, or Nimzo-Larsen Attack. Beginners are advised to play minimum openings repertoire.

I don't like randomly sacrificing my pieces or any strong attacks, then what opening is the best for me, and how should I improve?

I don't like randomly sacrificing my pieces or any strong attacks, then what opening is the best for me, and how should I improve?
Giuoco Piano is one option.
QGD is another
Nimzo-Indian is a third
I'll play Giuoco Piano first. That's the most familiar.
I somehow always lose when I play QGD, so I don't play it often anymore.
I am also not quite familiar with Nimzo-Indian, even though it's a good opening.

Ain't Beginners must learn Open games first? Why are Italian and Spanish openings popular? Why not taught or learned Scotch opening?

How to avoid blunders?
Sit on your hands. Seriously. That tip added 100 points to my rating.
This isn't a beginner question. Which would you ...
If you are not a beginner, why repeatedly post questions here?
You ask questions, I give answers