First, you need a mount point. As root: "mkdir /mnt/<nameyouwant>"
Then, mount /dev/hda1 /mnt/<nameyouwant>
should work. Your version of RH is pretty old, so if you're windows partition is ntfs, you're stuck, but for newer Linux versions, or older windows versions, you should be fine.
Also, SuperATA (or something like that...I'm tired), may not work without some patching.