This Arduino is small, and easy to use!!!
Specification:

Microcontroller : ATmega328
Programming Chip : FT232RL
Input Voltage (recommended) : 7-12V
Input Voltage (limits) : 6-20V
Digital I/O Pins : 14 (of which 6 provide PWM output)
Analog Input Pins : 8
DC Current per I/O Pin : 40 mA
DC Current for 3.3V Pin : 50 mA
Flash Memory : 32 KB of which 2 KB used by bootloader
SRAM : 2 KB
EEPROM : 1 KB
Clock Speed : 16 MHz

Download link:
Arduino IDE: http://arduino.cc/en/Main/Software

Package includes
1 x Arduino Nano v3.0 Compatible

Specs: