How was Goku able to teleport to the "Other World"? In DBZ, Goku has teleported several times to the "Other World" (a place presumably inhabited by souls), his most significant trip there being when he brought Cell in his second form there to prevent him from blowing up the earth and one another occasion Piccolo was summoned there too before being summoned to Namek. King Kai's planet is at the end of Snake Way and Snake Way is in the "Other World".

This brings about the question of where exactly is it located and wouldn't that mean that a 'dead' Goku could have easily teleported back to earth just the same as if he were alive?
He could (And he sometimes did), but it's "forbidden", and Goku doesn't like breaking rules.

It's actually a different world in the same "dimension" as the normal world, so yes, Goku can freely teleport between the two.