RFID part tracking

I am new to arduino so I could use some help getting my head around the components/programming that will be necessary to make my project possible.

I would like to have passive RFID tags be able to be placed on objects. Then have a timer start once the tag comes into readable range of the arduino + shield and stop when it goes out of range. I would like this data to then be output to a spreadsheet. Any help with the needed components or programming would be greatly appreciated!

-RFID tags
-Arduino
-Arduino RFID shield
-wireless SD shield