Electronics

I have seen already that some of you know a “thing or two” about computers.

Now, I know electronics are different, but I want to learn the basics of it.

So, I wonder wether any of you could shed some light about simple circuits and basics. So, first:

Do resistors decrease amperage as well as voltage, or only the voltage? I just couldn’t find anything that explicitly says that they don’t change amperage.

If I want to build a color organ, Will it be better to use a parallel circuit or a series-ed one?

Parrallel:

Power source
|
AMP<--------------signal
|-----------------|--------------|
resistor 1000resistor2000resistor3
|0000000000000|0000000000|
LED1 00000 LED20000000 LED3
(Ignore the 0’s, imagine them to be spaces)
When the leds are in different colors, and each resistor has mor OHM than its predecessor, and the amp regulates the voltage so the circuit won’t be fried yet still have enough power to operate.

Series:
signal
|
Power Supply---------AMP------------LED1-------LED2--------LED3

The idea is nearly the same, only that each led has a different minimum voltage value, so if the voltage is batween 0.4-0.45V the first will light up, and if it is batween 0.4 to 0.6 the second and the first will light up.

Anyway, I have probably done something wrong, either expressing my ideas, the ideas themselves, or just a wrong forum. Anyway, if any of you can help me, I’d appreciate it much.