Integration between SAP HR and BW

Hi Peers,

My company requirement is to put all the SAP HR data to BW server and all the reports is to be prepared from BW end , Now I have to Migrate my SAP HR data to BW and I dont know a single bit of BW , Pls help me with any information is useful for me.

Little Bit I collected from Net but it is not enough.

Pls help.