I want to bring my parents here for visit. I looked online and have found some resources. However, I have heard various suggestions from people such as writing/not writing a letter to USCIS, showing a bank balance of $10,000 etc. It would be of great help if anyone can give any information about the application process or share the link to a credible resource?
Thank you.

Since the last 2 years, the US embassy in Nepal don't look at any supporting document. They only look at the online filled form (ds-160). Even if you take additional materials at the interview, it will be useless as you won't be able to show them. That is also the reason it has become very unpredictable to get us visa.

Another point, they clearly mentioned they evaluate each candidate very carefully and efficiently so if your parents has good tie to return back Nepal and your status has not red flag, more likely will get visa, but sometime luck also works my friend.
Good luck

What kind of carefulness?

I applied couple times three years ago, it was denied. I was recently naturalised and am planning to do again.
Any suggestion on how to present case?

One of my friend who is a Phd Student wanted to invite their parents for Masters graduation last December and they rejected their visa. Their claim was they don't have strong tie back in Nepal, infact, their other son and two daughters were back in Nepal.

I applied for my parents visa 3 weeks ago for my Phd graduation in May. They also rejected both of their visa saying they don't have strong tie to come back.

The gist is they don't look at anything except all the information on the DS-160, so I don't even know how to prepare the case. They hardly ask any questions, in my parents case, they asked two questions, why you going and who else is back in Nepal. That is pretty much it

The US Embassy Consulers are a bunch of incompetent people who issue a visa with a roll of a dice. I have enough evidence. Family tie reason is BS.
I knoow few people whose entire family (including siblings) are in US and got the visa and I also know people whose visa got denied who have business in Nepal, No one in Nepal and genuinely did not want to stay in the US. Hopefully, you will get lucky. Good Luck.

Dnt ask both parents apply together ..applying separately makes them feel they will return back n strong tie back home...never ask ur parent act oversmart during interview ..I mean even if they can understand English ask them use translater n speak Nepali only..this way It will make them feel like ur parent r not fit In Us to work..also ask them to use simple dress while interview 'its not a job interview so be simple as possible .they will not ask more than couple of questions to parents n a common question is how many kids u have..tell at least 3 , 4 is ideal n all r in Nepal except u...it's as simple ... Visa is done