Assembly language - how to start ?? - help~

im doing a project. it deals with a 8-bit ADC to convert my analog data into digitized data then the data would be fit into 8052. after processing, the digitized data would be output in 7 segment display.

analog data > ADC0809 > 8052 microC > BCD decoder > 7 segment display

i have no idea how to start off to write my assembly language code. anyone have a hint for me how to write it?? thanks!!