Arduino Compatible Parts Kit
Assembled Arduino Compatible Breadboard Kit
Once you've assembled the Arduino Compatible Breadboard kit by following the included instructions you're ready to start programming! What you have is essentially an Arduino Pro (5V, 16MHz) w/ ATmega328. This means you'll need an FTDI Basic or and FTDI cable in order to load a program to the board. You can find out more about how to program the board by reading this page on the Arduino website. After you've uploaded a sketch to the board you can use an external power source to power the board, but be certain that you unplug the FTDI before plugging in the battery/external power supply!
The ATmega328 included in your kit will have a sticker on it. The sticker depicts the how the pin names of the ATmega328 correspond to the pin names typically seen on an Arduino. You can use these pins just like you'd use them on an Arduino.