Hi Folks!

Preparation phase(FIRST TIME DRIVER INSTALL PROCEDURES)
A1. Download USB 2 SERIAL BRIDGE DRIVERS (choose adapted to your computer operating system CP2102 driver):
http://www.silabs.com/products/mcu/pages/usbtouartbridgevcpdrivers.aspx
A2. Download one serial terminal software. We like TeraTermPro (google for it). 
A3. Connect the a-gsm board with USB cable to your computer. Follow install procedure, if needed.
A4. Open your terminal software, connect to the (a-gsm) com port (in hardware is identified as CP2102 port)
A5. Set the proper communication speed: 9600bps, 8N1
A6. Close the terminal software. Disconnect the cable.

Cable it your Arduino/RasperryPI/other a-gsm project, in respect of a-gsm hardware tips.
Compile/upload your code.

AT EXCHANGE DEBUGING PROCEDURE
1. Connect the USB cable to your computer.
2. Open the serial (com/tty) terminal application
3. Check if proper serial port (described in A4) is chosen in the teminal software
4. Check the communication speed (9600, 8N1)
From this momment, you will be able debug the AT exchange between your prefered ucontroller and the a-gsm board.
Run your Arduino/RaspberryPI code. The AT exchange will be replicated into the terminal window.

Enjoy!

Dragos/Bucharest January 20'th 2015