Yes sir there are things to help you out with that issue. First thing I want to say is you need a fuse or circuit breaker at the battery before you attack any type circuit to it. Some install a 50 amp fuse or breaker at that point. Otherwise a short in any circuit will mean extremely hot glowing wires and possibly a fire. And if you have a fire on the water, there is no place to run too. So install a circuit interrupter of your choice before doing anything else. Most folks run a 10 gauge wire from the fuse/breaker to the helm. You would run both a red 10 gauge wire off the fuse/breaker to a buss bar or terminal block and a 10 gauge black wire from the negative terminal on the battery to another buss bar or terminal block for the grounds at the helm area. That allows you to branch off to other circuits. The helm can be anywhere you want the controls to be. The for example, you want to wire up a bilge pump, you connect a 16 gauge wire from one of the terminals on the buss bar or terminal block and wire it to a fuse or breaker for that circuit. The other wire out of the fuse goes to a switch. From the other terminal on the switch the wire goes to the bilge pump. At the bilge pump the ground gets wired back to the black terminal block at the helm area again. And there you have one complete circuit wired. The fuse size for each individual circuit depends on the amount of current in that circuit. Again the bilge pump would probably use a 5 amp fuse. So that is the size you would install. And you repeat that same installing technique for all the different circuit. Simple, safe and totally reliable... JMHO!
Here is a typical picture of a buss bar or terminal block;
Understand There are all types of terminal blocks you can use...