Maya - Screwdriver

First meaningful render i've created in Maya - well it means a lot to me! Somethings happened here today, actually i've just followed a tutorial on the link below. Need to figure which mode to save them in to give the best restults. Tried a Tiff - blog wouldn't accept it, a Giff had a naff resolution, so used a jpeg, which isn't ideal. (http://www.highend3d.com/maya/
tutorials/modeling/polygon
/How-to-model-a-screwdriver-and-
render-it-with-mental-ray-239.html)