What about company verification and company check?

How do you usually find companies’ data? What strategies do you use? Do you search manually every company name in Google or other search engines or visit various B2B websites and many web pages to get companies’ information? 

What about the time you are confronted with long lists of company names that must be converted to their contacts? Can you search hundreds of company names in Google one by one in search of their contacts and any other kind of interesting data related to them? 

What about company verification and company check? Do you verify companies based on the data you see on their websites or B2B sites!? Are they really helpful in company verification? 

I myself always repeat in mind “Please not to trust any new company”. First, check it and then accept! 

How do you check companies and how do I get companies’ data? Do not hurry, I tell …