If your new to a dungeon.

[Niwashi]

I don't like to watch videos, because it spoils the surprises in the dungeon, but I still have to watch them because people complain too much if you don't know the dungeon.

Personally, I find the text dungeon guides in most wiki sites to be somewhat of a middle ground. They provide info about the major obstacles and mechanics you'll encounter, but at least your own run is the first time you actually see the place.

It's still a spoiler in the sense that you already know what to do and don't have to learn it the hard way, but it doesn't feel as much like a spoiler if you're getting to see the place for the first time as you run it. So I read up about dungeons before I run them, but I don't watch videos of them.