PCB layer stack up practices
I generally try to keep my signals on the outside layers and planes on the internal layers, though this is highly dependent on the design. Having capacitance between two planes is advantageous because it provides a little bit of immunity to noise on the supply line that could otherwise couple into the circuit. Sometimes you may want to shield traces carrying sensitive signals, in which case you might put those on an internal layer and put grounds on the external layers. There really isn't a one-size-fits-all answer - it is highly dependent on your particular design and what signals and components you have.

This is why it is very helpful to have a firm understanding of electronic systems and how environmental factors and parasitics affect signal quality when designing PCBs. Without this knowledge and understanding you're effectively taking a shot in the dark at whether or not it will work as expected.


  I can't seem to find a good answer


This is because the "good answer" will be different for every design for different reasons.