I may be telling why it is happening incorrectly, so someone please feel free to correct me... but here it is.
Because NTFS does not support traditional UNIX type file permissions, and uses Security Identifiers (SID) to enforce ACL's, Unix does not know how to assign user and group permissions to the mount. As a result, all files are automatically (and temporarily as not to damage the guest file system) set owner and group as the user who mounts the files. In this case, root!
As a normal user, you cannot read/write root's files. The workaround for this is to mount the file system with umask constraints. I'm assuming this is a single-user computer, and so setting a umask of 0000, which is essentially read/write/execute for user/group/all.
mount /dev/hdb1 /mnt -o umask=000
This should mount the filesystem so you can now read it as a normal user. Keep in mind, this allows *any* user to read the files... and like I mentioned earler... could be a security issue.
from there, you should be able to add fstab entries to ensure mounting at bootime. Something like this:
/dev/hdb1 /mnt ntfs user,umask=0000 0 0
Hope that helps you out! Good luck!