Embedded Systems - ADC QUERY

HI FOLKS,

Could any one guide me to a decent article on collecting data with the help of a microcontroller ADC.I had worked with MSP430 microcontrollers for the last year and a half and have always found the data observed on the registers of ADC to be fishy and not reliable.Is it because of the real time event that I am not able to look at reliable values.Please do share your experience with me.

Murali.