Hi everybody, i'm back in the Ubuntu-realm after a few years of being away. Good to be back [a single tear runs down my cheek].

A lot has changed, it seems and I've been reading up on UEFI, secure boot, Ubuntu 12.10. I bought an ASUS A56C laptop preinstalled with Windows 8, it'd like to dual boot with Ubuntu Studio.

From what I've read it's best to shrink partitions in the windows disk management tool, restart windows, and then install Ubuntu to the empty space. My question is can I safely delete the D: partition (named "Data") or is it necessary for windows to run?
I don't think it is because the C: partition called OS seems to have all the windows system files. I have no data on partition D, it's just taking up space. I'm aware that this is technically a windows-question. I just wanted to make 100% sure.

My second question: is it correct that as windows 8 was preinstalled in UEFI mode that ubuntu should also be installed in UEFI mode?

What about secure boot? should that be disabled or does it not really make a difference?