Actually, gmax is pretty much the same thing as 3ds max, but you might find some things are in slightly different places (also depending on the version of 3ds max you compare it to). The only major differences between gmax and 3ds max are that gmax doesn't render, doesn't have character studio, doesn't have many plugins for it, and doesn't save in the same file formats. I picked up a copy of gmax myself and there were tutorials available from the discreet website, so you might want to make sure you go through those to familiarize yourself a bit more with the gmax interface. Afterwards, you should be able to use any 3ds max tutorial and be able to apply it to gmax.