Do the partition shrinking in Windows, create the new partition(s) in Linux.
How to do the divisions is up to you. I can't remember how I've split them up before but I think I had one partition for the root directory (/; maybe 10-20 GB?), one for /home (~30 GB), and then most of the remaining space became a shared FAT32 partition. But my drive was probably smaller than yours, distributions have probably gotten somewhat larger, and Linux has pretty solid NTFS read/write support that it didn't have back then. You can make Windows read an ext3 partition but it's probably easier to do things the other way around, at least when it comes to files you legitimately want to share between OSes.
How to do the divisions is up to you. I can't remember how I've split them up before but I think I had one partition for the root directory (/; maybe 10-20 GB?), one for /home (~30 GB), and then most of the remaining space became a shared FAT32 partition. But my drive was probably smaller than yours, distributions have probably gotten somewhat larger, and Linux has pretty solid NTFS read/write support that it didn't have back then. You can make Windows read an ext3 partition but it's probably easier to do things the other way around, at least when it comes to files you legitimately want to share between OSes.