i recomend u to read mazidi's book of 8051 microcontrollers
Added after 24 minutes:
u can do the following pro
Solar Recorder
and get the information from the following page
file:///C:/Documents%20and%20Settings/STUDENT/My%20Documents/proo/Solar%20Recorder.htm
read the ADC values from sensor or changing the potentiometer. read from controller display on LCD and store it in eeprom or send it through serial port to hyperterminal, set a value for the sensors. if the adc value = max value set for the sdc channel generate an interrupt.
So you will have exposure to LCD, adc, I2C and serial comm.