Everyone goes about researching names and niches differently, but here's a basic 3 step process you can follow:
1. Go to Namebio.com and check to see sales similar to the name you're thinking of bidding on.
2. Do a whois lookup on the name to find out the age, where it's registered, etc by going to whois.domaintools.com
3. Find out if there's competition in that specific niche, for example if the name is Dronezville.com, then look up drones on google and see how many sponsored ads it triggers. If there's a lot then that means that's a good market to be in because companies are spending money to advertise in that niche.