I've just installed CentOS 6 i386 from liveDVD iso. One reason why i chose CentOS 6 is the support till 2017 and i do not wish to do repeated installs. Previously i used openSUSE 11.0 (without upgrading) for 3 years even though support for 11.0 ceased in July '10.
I am just a single desktop user - so no major worries. I chose a comparatively larger /usr space as i plan to install bulky software like matlab, maple, sage etc in /usr/local.
Will the 10Gb for / be generally enough? Right now / occupies 5gb. Otherwish i have to reinstall.
And oh - i don't know what this means but system -> administration -> kernel crash dumps says 'Don't know how to configure your boot loader'. Is it a point to be bothered about? I thought that during 1st reboot i saw some FAILED thing about kdump.
I'd also recommend that you investigate LVM as this allows for far more flexible use of disk storage than just partitioning it. With LVM you can add new logical volumes, resize existing ones and remove old ones, all without rebooting.