GnomeBaker is a free CD/DVD writer for ubuntu gnome.It’s easy to burn CD/DVD in ubuntu with Gnomebaker.
First,just run this command to install GnomeBaker
sudo apt-get install gnomebaker
Then,at right top of your screen,click to Applications->Sound&Video->GnomeBaker CD/DVD writer to open it up.
In tools menu,you can select burn date,audio,.iso image CD/DVDs.Select one,then add the file you want to burn at the middle of this screen.