Simply ground the test light lead, and touch each side of the fuse with the probe end. If it lights on one side, It MUST light on the other side, or it is bad.
If it doesn't light on either side, try turning the ignition key to ON/RUN. Now at least one side should light up. If not, it might be a spare, (unused) fuse.
You can find your fuse panel descriptions under the "roadside emergencies" section of your owner's manual. If you don't have a manual you may download a 1996 and newer one for free from here
If you don't have a test light, you may pick one up at a $ Dollar store for a Dollar.
You may also use a volt meter. Just ground the neg pole, and test each side of the fuse as noted above. You should have battery voltage on both sides of the fuse.
Please note: Often one fuse in the battery distribution box (under the hood) may supply many fuses in the Central distribution box (inside the cab fuse box). Therefore if many fuses inside the cab do not have power, it may be because you didn't turn the key to ON, OR there may be a blown fuse in the under the hood battery distribution box.
Please see the photos below for additional info.