AVR ADC Example

Input Scanning
http://www.electronics-base.com/index.php/avr-tutorials/analog-digital-converter-adc/102-avr-adc-inputs-scanning-example

ADC atmega 328
http://www.embedds.com/adc-on-atmega328-part-1/

Multiple Channels
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=101325