It's been a while since I last bothered with partitioning my hard drive, but now it's time again and I remember last time I did this there was a requirement to put the root partition (or only GRUB?) not behind a certain cylinder number. Is this still the case or could I basically put Linux simply at the end of a drive?
That is not a Linux problem, but a BIOS problem, which affects only quite old systems (the first limit was about 504MiB;
At any rate, that affects only those components which are read by BIOS means. As soon as the kernel (including the modules for disk access) is loaded the Linux drivers are used which do not have this limitation. I.e. on affected systems you must keep all GRUB stages and the kernel and initrd files below this border.