Arduino "DO NOT'S"?

usually you would not connect the pins directly to each other, but put something in between, like switches, resistors, potentiometers and so on.

If you want to read a switch, you would connect an i/o (i) pin to 5V but with a pull down (or up) resistor.

But it's really a bad idea to connect the + 5 volt pin to the ground pins. It's also a bad idea to try to source more than 40mA from any pin on the board by for instance trying to run a DC motor or relay directly from a pin.

If you are very new to Arduino and electronics i general Lady Ada's tutorials come higly recomended.