No doubt the only correct way to use the processor from this family is to apply the negative logic. This term only means that high is the inactive state (or steady state), while all activations shall apply low state of the processor.

This should be used for both inputs and outputs. The switches (with or without a resistor to VCC) should connect to GND and not to VCC. Such a port must first be written 1 to, but by default, all ports start with all ones. For outputs (unless some of them are also tied to some contacts to ground) you can use the positive logic as well (0-inactive, 1-active), but it's usually better to be consequent, even at the cost of some inverter. (Nevertheless, this is what I usually do).

Regards, Slobodan