There are various tool for disk management in Linux. But the one I love is the gnome disk utility, a simple, powerful disk utility for Linux. Even it was designed for Gnome, but we can install this on Elementary OS Luna as well.
Ok here I just want to show you how to create new partition on a flash disk or hard disk and format it to NTFS file system. Please be sure that there is no data inside your disk. This task will destroy the content of your disk permanently.
First, install Gnome disk utility with this command:
sudo apt-get install gnome-disk-utility
Now insert the disk/flash disk and open the program. If your disk are not partitioned yet, you must create the partition on the Drive.
Click the disk on the left panel and press Format Drive. Next, select Master Boot Record on the new opened window and press Format. This will erase any partition on your disk and create a new layout.
Now we need to create new partition on the disk and format it to NTFS. Click Create Partition and select NTFS on the configuration window. Specify how much space you wan to use for this partition. You can also use the whole space if you want.