I have a set of these
I want to use them to light my bed. I think I want to wire them to my battery but I'm ignorant when it comes to electrical matters. I know I need an in-line fuse and switch to mount in the bed. Otherwise, I need guidance on what gauge wire, how to connect everything, materials, etc. Any help would be appreciated.

 

That is the exact same light string that I got for my truck. My truck is the one in the review photos with the welder in the back.

You're going to need power. I added a 3 outlet power socket in my bed(above the fire extinguisher), so I ran a dedicated hot line from the battery to the void behind the rear tail light.
There are quite a few options other than running a dedicated hot line: If all you are doing is powering this strip of lights, you could simply pull power from the parking light using a wire tap. This would mean that the bed lights would only work when the parking lights were on. A third option would be to tap the power coming into your 7 prong trailer plug. I believe this is only energized with the ignition on from the factory, but by plugging in a relay in a certain socket in the power distribution block by the passenger kickplate, it can be made to be always hot.

So to recap:

1) Hot line run from battery w/ inline fuse.
2) Wire tap from the parking light
3) A: Tap off trailer plug - hot w/ ignition On only
3) B: Tap off trailer plug - hot 24/7


Look for a 19mm diameter round switch. It will push into the top hole at the end of the bed rail. In photo, mine has a red LED when it is turned on.
This would be perfect:
The strip you linked will reach about 90% of the way around the sides/front of the bed. I used small zip ties to secure the strip to the plastic clips of the bed rail caps. I used the adhesive of the light strip to stick it to the front bulkhead. Make sure to wipe the metal clean.



As far as wiring/connectors:

18 gauge wire will be plenty for these lights. As you know, the leads on the light strip are phenomenally small, so the lights can't draw much power. Length depends obviously where you're pulling power.

Wire taps: These will enable you to piggyback off of a circuit.

Connectors. You can get an assortment, but what you will need are the small red butt splices

, small female spade connectors to slide onto the switch terminals

, and a ring terminal if you are going to ground to a bolt on the body

. Another option is to use one of the wire taps to tap into a ground wire of the parking lights or trailer harness. Use the red colored insulation terminals, as those are for small gauge(14ga. and smaller) wire.