can someone explain putting pawns on light vs dark squares

Normally you don't want to put your pawns in the way of your Bishop (the concept of the Bad Bishop), so you will put them on opposite colour. But everything depends on the concrete position. 

its a catch 22.  if your pawns and bishops share a color, they can defend each other, but the bishop is blocked by them.  If they use opposite colors, the bishop has mobility, but is useless to defend the pawns and cannot be protected by them.   When you still have both bishops, its even more complex: the bishop pair is strong but a bad bishop is bad and making the decisions to trade one, keep both, and how to align your pawns to support the choice are not trivial at all and unfortunately are heavily tied to the position in question not a rule of thumb.  I actually have tailored my openings to ensure that most of the time I have 2 good bishops, but not all openings support that idea. 

And you should not underestimate the Knights :-)

If you have only a light-squared bishop, you generally want to place your pawns on dark squares. This way your pawns control the dark squares and your bishop covers the light squares. This is efficient. If your pawns were on white squares they would obstruct your bishop and you would be leaving the dark squares open for your opponent to invade.  Obviously the reverse is true if you have a dark-squared bishop. 

Put your pawns on the opposite color of your bishop.

I think you're right about the colors of the bishops at the basic level but I think at a higher level, you have to know when you can/have to push your pawns up

     It is best to put pawns on the opposite color squares from your only bishop. If your pawns and bishop are on the same color squares, you will have no influence on squares of the other color.

     However, in endings with opposite-color bishops it is often better to put your pawns on the same color squares as your bishop. Then your bishop can defend your pawns and your opponent's bishop cannot attack your pawns, nor can it help its own pawns advance. This especially important if you are down a pawn or two.

#8
Bad bishops protect good pawns

just played a random line to show the point. this is a middlegame and black has just given up his dark squared bishop, and so he puts his central pawns on dark squares to cover the squares his remaining bishop can't and thereby complementing that remaining bishop, and also trying to limit the mobility of the other guy's dark squared bishop.

in the endgame it depends on the situation. if you put the pawns on the opposite color of your remaining bishop, they will still complement each other in terms of squares they will control, but if those pawns get attacked it would be more difficult to defend them.

if you place the pawns on the same color as the bishop, you may be able to defend the pawns but then you limit the bishop's scope. if there are other factors in the position this may not be so important, but if it's a battle of say a bishop vs a knight then this may very well be enough to lose the game.