I am trying to play with servos connected to Micro Maestro 6-Channel USB Servo Controller.
I correctly connected 2 servos (ground-to-ground etc) and I fired up Pololu Maestro Control System.
Unfortunately, when I slide sliders for according servos in Status tab nothings happens.
My question is - do I need to do something more? I read powering guide here: pololu.com/docs/0J40/7.a but what I understand is that my servos should use power coming from USB, is that right?
What I would like to achieve is to be able to control servos using USB cable w/o any additional wires or power supply.
USB is not sufficient for powering servos: there is, for example, a current limit of 500mA or less. You might be able to power a single servo this way as long as it is never stalled, but you would risk damaging your computer or the Maestro. So, unless you really know what you are doing, you should probably follow one of the connection options on the page that you linked to.
The 5-16V range is for supplying Vin, not for the BAT voltage. Since whatever you put there is just connected directly to the servo power lines, you need to pay attention to the requirements of your servos instead of any Maestro specifications.
I should additionally point out that both servos will be connected directly to 9V and GND if you do what you were suggesting, so they will both see the full 9V. There is no way to divide your voltage down by distributing it between multiple servos.