mount /dev/hda1 /mnt/windows_c -o umask=0
Now your files will be in /mnt/windows_c. 'mkdir' makes a directory, the mentioned 'mount' command mounts your first partition on the first hard drive (hda1) to the newly created directory. The '-o umask=0' lets regular users access. To do all this automatically on startup, search for info on the /etc/fstab file.