I highly recommend this DVD. There is a very cool featurette called "Making of the Suit" where they describe the three models that were used to eventually formulate the final look of Godzilla.
The Serpentine Godzilla
The Warty Godzilla
Alligator Godzilla (which was used to create the final costume) Notice that the skin is gnarled with no particular pattern. Was used so that it would resemble a creature created by the crippling effects of radiation.
