Master Data

Hi, i have few basic doubts, can someone help me with this

I need to know how to bring in Master data before we work on any info area and is it necessary or a must that we bring master data for any info area that we work on.

and is the method tranfering from rsa5 to rsa6?

and once we bring in master data do we have to activate it and then create the infosource and assign source system for the info source and then load the data?

Can someone explain me what we do when we start working on a info area fresh on r/3 and bw side.

Thankyou.