I'm not entirely sure what goes to / and what goes to /home but it appears that /home is taking more space.
Home is all of your user files, which will include configuration settings and the default Pictures, Video, Documents etc. folders. / will be system files, installed software etc. 92G seems like a lot for that (Mine is 6G) I think you would be fine with half what you have at least. Boot is all of the stuff needed for booting. This is often on a different partition if you are using encryption or lvm on your other partitions (which would make them inacessible at boot time).
If you want a good graphical tool for faffing with partitions, I have often used gparted from a ubuntu live cd/usb.
Home is all of your user files, which will include configuration settings and the default Pictures, Video, Documents etc. folders. / will be system files, installed software etc. 92G seems like a lot for that (Mine is 6G) I think you would be fine with half what you have at least. Boot is all of the stuff needed for booting. This is often on a different partition if you are using encryption or lvm on your other partitions (which would make them inacessible at boot time).
If you want a good graphical tool for faffing with partitions, I have often used gparted from a ubuntu live cd/usb.