allrignt, first you need a multimeter, ($8-$12). This tool is great for testing simple electronics. It has an "ohm" setting that measures resistance. What happens is the multimeter in the ohm setting will tell you how much resistance to electrical flow exists between the 2 test leads. with out the leads hooked up to anything they give a reading of infinity (often displayed as "l" or "OL"), if you touch the leads together you get a resistance of "0" as there is a clear circuit between the leads. So you take the leads and touch them to the terminals on your light bulb, it should give you a resistance reading. The other method would be to set it to DCV for measuring Voltage, and check across the plug that the light hooks into and see if there is voltage present.