Hi, and welcome.
Did you check the md5sum of the CD(s)? If they don't match, you will need to download again. Also, I would suggest using wget with the -c option to download, since it will resume if necessary.
Also, I've found in the past that for reliable results with bootable CDs, I need to burn them using the slowest rate I can. If using something like Brasero or K3b to do the burning, I would also set the software to check the CD when the burn completes.
Good luck.....
Whoops... Should also have said that 6.0 Standard god does not have a live CD at this stage (

at least, not unless something has slipped past while I wasn't paying attention). The first CD is an install CD with a graphical install program. Optionally, you can select a non-graphical install, which may suit some hardware better.
paul.