Some suggest trying gmax out. Its max watered down. Its a pain to bring a ship into mod format. I haven't tried it yet but its free. Do a search for it.
I use milkshape. Price went up to 25 dollars. there is a 30 day trial period. It can make decent models. Its the easiest to learn. You can use some of what you learn later if you get max. For an example of a milkshape model-check my Norway thread, takes a bit longer to model in milk perhaps but the price is right