I'm not sure what I should do, I have one battery runing my electric start motor and trolling motor I'm gonna have a bilge, nav lights, cockpit lights, and stereo all ran to it too. How should I do the wiring? Should I have a switch panel for the lights and bilge? Do I need fuses what's the easiest, safest way to do this thanks.
Engine wiring is typically self-contained in the wiring harness.
The bilge should have a fused feed direct to the automatic float switch from the battery and a manual feed through a manual switch with preferably a circuit breaker.
Trolling motor should have a breaker right on the battery for that circuit.
I prefer to have one large power feed daisy chained to individual dash mounted circuit breakers that then feed individual dash mounted switches for anchor light, nav light, bilge, bait well, cockpit lights, etc all mounted on one front removable panel. This eliminates the need for a power distribution panel. (The panel is replaced by the wiring that daisy chains to each breaker.) Breakers are better because you can reset them. It is also much easier to maintain and/or repair down the road.
The main concern is providing a large enough wire to provide the main feed to all the breakers. Add up the actual load for all your electronics and size the main feed wire and breaker for 25% over that. (NOT the breaker sizes) For reliability and extra short circuit protection, feed both ends of the daisy chain. Then if for some reason you have a bad connection in the chain, power will still feed from the other side.
Actual loads and recommended short circuit protection is typically included in product specifications.
For things like trim tabs and the stereo I would put them on circuit breakers too. Fit them in with your other switches if you have room, else wire tie the breakers under the console with enough slack to work on if you have problems.
The place that gets ugly quick is where you connect all the negatives. These are NOT on the breaker/switch panel. Distribution panels make this easier, but you can accomplish the same with ring lugs stacked on one nut and bolt. Then wire tie that into your wiring bundle and you don't have to mount a bus bar that will be a pain to get to forever.
Look at the pictures of switch panels on Maverick's websites and you can see how they did it.
All they have is a battery switch and the main fuses under the console. Everything else is on the back of the switch panel that removes from the outside.
http://www.maverickboats.com/boats/mirage-17-hpx-v/#gallery
There are many that like power distribution panels, and there are many that are sold. I'm just not a fan of them because I feel they put too many eggs in one basket that is usually hard to get to and impossible to repair.
I fished with one battery for TM and starting for quite a while. Then I went to Flamingo and realized that was too risky on multi-day, backwater trips.