You need a /root partition and a small /swap partition to install Linux.
It's a good practice to create a separate /home partition when installing as
then you can keep all your settings and data when you upgrade. The Linux
operating system can read your Windows files, but Windows doesn't know
anything about the Linux filesystems, so if you want to use data with both
put it in the Windows partition.
Settings? Use the default ext4 Linux file system, maybe 10 GB for /root and
as much as you can spare for /home. You may be able to enlarge either or
both later with gparted if necessary, but only when you are booted from a CD
or other linux op. system.
Ask some more questions if that isn't clear or complete enough.