Residence and Work permit

Hi
I'm going to work in China for 6 months on a z visa.
Firstly does anyone know the cost of the residence and work permit applications once I'm in PRC? Also there are many sites that list the documents needed for the permits but no where does it explain what these are, the content and for some of them, where to obtain/apply to. Eg there are various departments that need to issue certificates/letters etc. is there anyone who knows of a site that clearly spells these out in detail?

Thank you!