Sorry for the quality of the pictures. All I have available is my phone camera. Everything is already installed, which makes it more difficult... For my GPS, i used the WIPER fuse.
Here is the passenger side fuse panel. The positive wire off the power extension is in green, for visibility. The ground is in yellow and runs from the end of the power extension, through the wire loom, to where I grounded it. I have a picture of that below. For the end of that wire, I got an end that was a metal circle, crimped it on, and put the bolt through the center and tightened it back into the frame. (There are two power wires because I have another wire powering my gauges. You should only have one add-a-fuse wire)
Here is the add-a-fuse pulled out. the original fuse goes in, as well as a new fuse rated for your application. The additional fuse should be of the same value or less as the fuse that you are tapping, not to exceed the rating of the add-a-fuse. To ease installation, I ran 18Gauge wire from the add-a-fuse to the other side of the car and attached it to the end of the power extension. That allowed me to run the wires without stretching them.
Here is where I grounded the circuit.
This is a shot on the drivers side looking under the dash. The power extension plugs directly into the car adapter for the GPS unit.
Run the gps wire up the drivers side of the dash to keep hidden.
Pull out enough so you can attach to the gps.
Sorry for the terrible write up, but if you have any questions, let me know. It is a pretty simple job. I used heat shrink on all the connections where I put two wires together, or added some kind of end. I tried to wire loom all of the wires as well, so they don't rub on anything. In all, it took maybe 30 minutes.