I trust you really tried to mount sdb1 and not sda1? Have you created the /mnt/usbdrive folder (or any folder you want to mount the drive into)? As you have an NTFS filesystem you may have to install ntfs-3g. Then if you search the forum for ntfs-3g you'll come across this post
with the correct syntax to mount an NTFS drive. If you need to install ntfs-3g try:
yum install ntfs-3g --enablerepo=clearos-epel
Try first without installing the package.
Note I have never mounted an NTFS disk before so this is a bit new to me as well.