Oracle Database Discussions

Hi

I am trying to install Oracle 10g (Linux) in my Fedora Linux 10 i386 OS. I have understood the Kernel setting etc. When I proceeded to learn about creating mount points and relevant directories such as ORACLE_BASE and ORACLE_HOME, I am kinda confused on where do I do it. I have been logged in the root directory but then I was asked to create an Oracle directory as well. So, where am I exactly creating these ORACLE_BASE and ORACLE_HOME directories and further sub directories like u01, u02, oradata, cdump, udump, bdump etc. ?

I am really confused. Please help me undertand this.

THanks

Nischal