chmod/chown are your friends
There are a few things you can do.
1. make the mount point owned by user/group steve. do this with the drive UNMOUNTED.
# chown -Rf steve:steve /path/to/mount/point
1a. you might need to look at the df -Th command to see its exact mount point. it will look something like this:
[user@centos ~]$ df -Th
Filesystem Type Size Used Avail Use% Mounted on
ext4 50G 4.8G 43G 11% /
tmpfs tmpfs 939M 0 939M 0% /dev/shm
/dev/sda1 ext4 485M 144M 317M 32% /boot
ext4 1.8T 1.4T 277G 84% /exports/centos
/dev/sdb1 ext4 1.4T 1.2T 131G 90% /exports/NFS_TV_Shows
in the last line you can see a non-LVM mounted internal HDD. your external will look very much like that. it will be /dev/sdX# at the beginning of the line and /path/to/mount/point at the end of the line.
2. set the permissions on the mount point.
# chmod -R 755 /path/to/mount/point
3. manually mount the external drive. the reason for the manual mount is so that you can change the permissions on the drive it self.
# mount /dev/sdX# /path/to/mount/point
so in my system that command would be:
# mount /dev/sdb1 /exports/NFS_TV_Shows
4. repeat steps 1 and 2 above with the drive mounted. Then you can log out of root from the terminal and you should have access to the mounted drive as user. Keep in mind that the user still does not have normal permissions to mount/umount the device. In most distros that is reserved exclusively for the root user. You can modify the sudoers with the mount/umount for the mount point.