120 VAC Voltage (RMS) Data Logging Guidance (Repost)

So this is my second time posting, I would like to make a 120 Volt AC (RMS) Data Logger has anyone done this or attempted it? I am looking for needed components I have an Arduino UNO R3 and a Data Logging Shield but I dont want to re-invent the wheel when it comes to the Sensor and its components.

What do you want to log? Voltage, Amperage, Wattage, PF? Have you checked:
OpenEnergyMonitor