Lets say I have one servo that can operate at 3-5 volts and another at 3-7 volts. My power supply being 4 AAs is 6 volts. If I want to power both servos through the same supply, how do I do so without burning up the first one? Thanks and Sorry for newbie question :).
I suppose you could use a buck converter ( about a dollar US on Ebay) and drop the 6V from the 4xAA to 3-5V/
Then just connect both servos to the lower voltage and you should be fine/
Current draw is another matter though! 
i want to try this thing, can anyone help me with programming please.
is there a way I can drop the voltage in some places on the breadboard and up it in other places?
What is your servo voltage? If you have a 5V Arduino and a 5V servo why would you need a lower voltage?
Something like this will give you 5V on one side of the breadboard and 3.3V on the other but can't supply a lot of power, about 700 mA, you would need more to power a servo.
hi. if you dont mind.i have a question about powering 5 servos. i think it is better to apply 5 voltage and 2 amp. what will happen if i apply 5v and 3.6 amp from my power supply.thank you in advance
Having a power supply that is capable of supplying more amps than you need is never a problem The devices will only take as much as they need.
Not having enough amps available would be a problem.
...R