To start with, you will need an ADC, to check your voltage, a current sensor (it can be a hall effect sensor, or a current transformer). For reading temperature you will need a temperature sensor( may be a RTD will do for you or an LM35 IC which gives you an analog voltage based on temperature, so here again you need an ADC).
Obviously you will need a LCD, a microcontroller and based on your data logging requirement other components. I'm sure you can start with UART communication over PC. you can use FTDI232 for that.