Let me preface my questions with a statement of my electrial ability: I can wire lamps.
I am looking to use a West Marine Distribution Panel for the 12 volt in the Nookery. At present one switch will be for the reading lights and one switch is going to be dedicated to running computer fans in the overhead vent. The final switch will most likely be for some outdoor lighting.
This is the instructions. I followed everything, but there doesn't seem to be a ground area for the appliances shown. Or a black wire feed to the battery.
Here's a front shot of the panel. Pretty much does everything I thought I would need. I bought it probably 5 years ago. The fuses are the little glass ones. They are each rated for 15 amps.
This picture isn't very clear, but there are two open spades. The higher one is to the positive side of the battery. I am guessing the lower one is for the ground to the battery and grounds for the lights and fan. Should this have a buss bar too? To connect all the grounds and then connect a single ground to the panel? Or is that complicating the actual wiring?
Last shot is of the three spade connectors for the appliances, as the directions call them.
I have the black plastic cover to house the panel in. I will need to drill an access hole, so I want to wire things up and test it before I commit to that. All the lighting is LED. The fans will be wired in such a way that I can use the type switch that is used to raise and lower things. Sorry, the correct name escapes me right now. I also have the switch. Well, it's somewhere in the camper parts inventory pile, anyhow.
The outdoor lights are two of the LED under car lights that I picked up for another trailer (long gone) and would like to mount underneath the trailer to give light and maybe keep the critters at bay. I would like to wire them so they will come on together.
Simple, right? I'm pretty sure I need the bus bar, or someone to explain the finer points of wiring a panel. I tried Youtube, but all the vids are a bit lacking on the actual wiring details.

Thanks for your help!