This is a chooser for finding firmware. If you enter "optical drives" and "SHM-165P6S", it will take you to a page and offer http://www.liteonit.com/DOWNLOADS/ODD/SHM-165P6S/firmware/DR16MS0N.zip
Which should be the correct firmware for you. Follow the driections it gives you.
Regarding your question of which is better Kprobe or Nero, I prefer Kprobe as it makes it easier for me to catalog all of my scans (I scan every burn) while Nero has some nicer graphics which are good for doing testing--it can overlay the burn speed on the graph which shows the scan of the disc. This is useful for seeing certain kinds of problems. Use whichever program you like, it will make little difference.
There's nothing wrong with being new. We were all new at this, once. I made the mistake of buying a sony DRU-710A. The mistake wasn't the drive, but buying from Sony--who has the worst tech support I've ever had the problem of working with. It took 5 firmwares before they got one that burnt very well. I've probably made 50 coasters because of their horrible early firmwares. Not I use one of CodeKings custom firmwares and I am a lot happier. But, I've had a year and a half to learn about DVD burning and to make the decision.
This message board is a good resource. Use the search tool when you have questions. For the first few months, you'll probably find that any question you have has already been asked by someone who came before you.
Best of luck!