LED Matrix design without micro-controller
If you are controlling each LED independently then each should have its own resistor.  If you are controlling a whole line/string at a time then using a single resistor per line may work out well enough.  

Position does not matter as long as the resistor is in series with each LED or string. The only issue that might change this is if there is a chance you could short an LED line to ground and cause an over current condition, in that case you might want to place the resistor(s) on the + supply side.