a really quick effective way of doing a clay type render (no textures) is the following(im not sure if it is just in maya7 or not)

make sure there is a plane below ur character

select all objects in scene and place in a render layer.

select this layer and right click hold over the flag icon, select presets and occlusion.

as long as u have ur render layer selected then ur objects should look black

click the sphere icon on the layer-the arrow by the out color and bump up the samples to 32 or more depending on how long you want the render to take..then render away...any problems gettin this to work let me know but it makes your models look the nuts without havin to deal with lighting and textures.