Welcome to LQ! There are three common issues with failed burns:
1. The downloaded image was corrupted during transmission. Fix: be sure the compare the checksum of the downloaded image to the correct checksum listed on the download site. This is also known as the MD5SUM. Unless the numbers match exactly, the image is no good - delete it and try again.
2. The .ISO was not burned as an Image file. Fix: don't burn it by dragging and dropping - be sure to burn it as an Image file
3. There was a problem during the burn. Fix: burns done at a high speed are far more likely to fail than burns done at a more moderate speed. Personally, I burn at a max of 16X, even though my drive is rated for 44X, and since burns are one time costs, taking, say, 3 or 4 minutes to burn rather than 1 or 2 minutes shouldn't be a big deal.
There could be other factors that could cause trouble, but the above 3 are the frequently seen. Good luck with it