That should work. 15GB ntfs & the rest for Linux. I'm not familiar w/ Suse but it should have an option during the install to use a boot loader. ie. Lilo or Grub.
You'll need to setup min. of 2 partitions ie. / & /swap this is again during the setup portion. Do not let the Linux install do this automatically, select the option for a custom install.
I'm more familiar w/ RedHat's distro's, at the boot loader part of the install it should let you select where to install the loader. ie mbr or under "/" partition. select the mbr, this will give you the option to boot windows or linux when you turn on your computer.
The reason someone above mentioned having a fat32 partition, is because Linux cannot write to ntfs, it will read but won't write. Also when you make the /swap partition make it at the end of the drive. Also it helps to install everything , because later when you start compiling progs. you won't have to check which lib's you have. Also some device drivers require them to be compiled. ie equinox & digi port cards. I'm guessing that the min. you would need to install everything would be 10 gigs. w/ a little space leftover to mess w/ stuff.
Regards,
Jose