If you wish to allow non-root users to write CDs, you must give them permissions to do so.

1) Give them permissions by setting SUID-root bit on cdrecord:
# dpkg-reconfigure cdrecord

2) Next you need to add your users to the cdrom group. New user rocky can be added as follows:
# adduser rocky

Once user added, add rocky to group cdrom:
# adduser rocky cdrom

3) Since cdrom group has write access to /dev/cdrom (/dev/hdc etc) and we have added user to cdrom group, rocky will be able to write cds.

4) Create an ISO file and write it:
$ mkisofs -v -o my.iso -R /home/rocky/mydata/
$ cdrecord -v -dev=ATA:1,0,0 speed=4 my.iso

Note as the root user you can mount an ISO file to modify or view its contains.

Related: Burning multi session CDs under Linux