Yes, it's a good idea to umount before you disconnect.
Have you tried
you should also read
and
basically it's
Code:
mount device mountpoint
but you may need to specify a file system, and there are other options you should read about too. For umount you can specify either the device or the mountpoint.
If you look in fstab
you can see all the options that are used to mount your filesystem at startup
mount is good