You will start the installation with a live-stick or live-CD. Choose install ubuntu. when it comes to partitioning, don't hesitate to manually partition your hdd, since you don't have to loose any data. Now you create the first Partition. leave the configs alone, just adjust the size and set the mount point to
/, so it will be your system partition.
Create Partition 2. (again, no config changes, just the size.) If you want to store your data in
/home should be on the second (data) partition, you can set the mount point of partition 2 to
/home. If you do so, everything saved in
/home/ like your personal settings and files will be on the second partition.
during install there's no NTFS-support. At this point that really isn't needed. If you really want to have a NTFS partition, create it later and leave the rest of the HDD-space empty. You can create the partition later during Windows-installation or by installing the NTFS-Tools and a partition manager like
gparted . *It is highly recommended to install Windows before ubuntu. Windows DOES NOT create any settings for ubuntu. It will be like you dont have it installed. Ubuntu in the other hand KNOWS all configs for windows and will create a boot manager to choose the booted system automatically on ubuntu install. *
Hope this helped.