To burn a .iso file:

cdrecord --scanbus

this will determine the address of the cd\dvd burner
it will be in the form 0,0,0 with the device name beside it

Example output of above command:

        0,0,0     0) 'ATA     ' 'WDC WD2000JD-00H' '08.0' Disk
        0,1,0     1) *
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *

Then use

cdrecord -v -eject dev=0,0,0 speed=8 filename.iso

if this does not work, try 

cdrecord -v -eject dev=ATA:0,0,0 speed=8 filename.iso

viola you have just burn your first .iso file to cd/dvd

!!!Note: not all versions of cdrecord or cdrdao are compatible with dvd burners.!!!

Further Note: in place of "dev=0,0,0" or "dev=ATA:0,0,0", you may need to specify the device (not the mount point) ie dev=/dev/hdc on my system