Your Windows C & D drives (partitions) together use 7.6 GB - so 2.4 GB are left over for Linux (assuming that U are not resizing the D partition (possible if it is FAT32 filesysttem)) .
Id then say maybe a 160 MB swap partition & whatever is left over for the Linux root(/) partition .
You are using suSE 9.1 (great 2.4 based SuSE
) .. so I guess you know that 64 MB RAM & 10 GB will still mean a bit of a slow system.
: If SuSE is too slow for you I recommend vectorlinux.com