[CentOS] Moving a Centos 5 install to another disk

I want to get Centos 5 on my notebook, at minimal risk.

I want to install it on a clean drive, make sure it 'works', the delete 
everything but /home (which is on a separate partition) from the Centos 
4 drive and copy the Centos 5 over.

Any 'caviats'?  I would first tar up the Centos 4 stuff before putting 
my foot into it.

To what extent do I need to have the same drive layouts?  Is it enough 
that /boot and / are consistant (ie each is in its own partition).  I am 
working with /home in a separate partition.

Thanks for the help!