If you can get that free version of Carrara, that is the best freebie I have seen for render engine.
Daz Studio is an okay product and free. The advantage to it are the freebies custom-tailored for it. I don't use it because I already spent $$$ and time on Poser and Carrara.
The Carrara 5 that is the free version is really worth the effort to learn (they are on to C6 now). The carrara 5 handbook by Mike De La Flor is available in libraries. Daz has a few carrara tutorials on their site.
