File - RFC - File BPM

Hi,

I am trying to make a scenario based on File-RFC(BAPI)-File but have some problems.

In the Directory how do I have to configure it? I mean how many Services do i need? Also which communication channels. Some blogs say I have to create 3 comm channels and 3 receiver determination? But how am I gonna use them? If any one has some document blogs or could post answers would be grateful. Thank you very much.