Not sure what to tell you about Carrara. Don't use it. Try searching google or something for
Poser Tutorials. Might help to also check other forums like
Renderosity, 3D Commune, and a couple others that do 3D work.
I use Max Studio for my stuff it's a killer on a computer. I am running a 1.2Ghz P3 processor with 512 MB SDRAM and a 128 MB Video card. And loading a Hi-res figure wil almost kill mine.
Posette and the lo res figures are fine, as long as you don't go to overboard. I would say to try it first Max 7 Demo is free I believe from
www.discreet.com, you can go there and even look up system requirements.