Basically, you don't need any instructions because the operation is pretty straightforward. You plug the device into a USB port on the PC. It is recognised and made available by the system in 99% of cases. To open it, press the button on the front and when it pops out, pull out the "drawer". Clean the CD/DVD, push it in by hand until it clicks and the job is done. Nowadays you don't need a special programme to burn a disc, just use the function built into the system.
AFAIK, there was no manual with it, just a two-page booklet. The device is a standard plug-and-play DVD writer, compatible with the most common software. What specific function are you struggling with?