How to create a partition inside an existing partition?

[David Le]

Hi,

Thanks everyone who answers my question about utility
to burn FC4 CDs. I was able to use Roxie to do that,
although it's not a free software.

I'm a new user to FC4 and I'm really impressed about
its functionalities. 

I want to setup a dual-boot of WinXP and FC4 on my
labtop IBM ThinkPad T43. There is one physical disk of
80GB and there were already 2 partitions (created by
IBM when I bought this labtop): Partition #1 (70GB),
partition #2 (4GB). 
Question: 

1) Inside partiont #1, I want to create partions
needed for installation of FC4. How can I do that
correctly and safely?
It would be appreciated if you can give me as much
detail as you can.

2) What is the reasonable size of partition that
should be reserved for running FC4?

Please let me.
Thank very much.

--david le.