This documents how to do this from the command line. I assume your CD burner is mapped to the device file /dev/sr1.
First, make an iso of the directory you want to burn:
mkisofs -r -R -J -l your-directory > your-iso.iso
Then burn the iso (check that root has write access to /dev/sr1):
sudo cdrecord -v dev=/dev/sr1 your-iso.iso
I basically copied-down the instructions from a YoLinux tutorial