Avatrs provided

[Karthi]

Hi!
I'm really having trouble getting my mesh of a male and female human to look realistic. I realise this is more of a graphics question rather than a Vizard questions, but do you know of any tutorials or any models of a human that i could look at? I have tried so many different ways, but nothing looks even remotely close to the avatars that come with Vizard.
Cheers
karthi