AC analysis of Amplifier
You can use the same way of DC analysis to calculate the voltage gain calculating the output voltage at different levels of input. but when it comes to the input impedance (resistance appeared at input of transistor) and  output impedance (resistance appeared at output of transistor ) it becomes more complicated when using more transistors and more stages (more levels  of transistors circuits).
refer to this link 

http://www.zen22142.zen.co.uk/Theory/re_model.htm