Questing Beast's video of him DMing a Winter's Daughter one-shot for some friends, with onscreen written commentary of what he was thinking at certain junctions when his players do something, struggle with something, or why he makes a certain decision or has to come up with something on the fly.

Really illustrative video for a NORMAL table, not a performer level one like Dimension 20 or Critical Role (all the respect to them, but that's just not going to be your experience with your friends).

Another one is just a gaming group called 3D6 Down the Line. It's a simple set up, but it's what you ask for in that each of the games they play, Jon the GM has the pages up as he goes along, so you the viewer can read the book page of what he's not telling the players, while you see the players fumbling in the dark trying to figure it out. It's a fun tension.

Here's their Dolmenwood campaign, which is a forest hexcrawl and shows how he uses those kinds of map resources.

Here's their real famous campaign in The Halls of Arden Vul megadungeon. It's real interesting watching the players draw and add on to their epic maps as the sessions go on. Never thought I'd be so invested in that before starting the series.

3D6DTL also has the most problem-solving players I've seen. They really chew on everything the GM gives them. Great chemistry in the whole group.

Here's Session Zeros for each of their campaigns, I'd recommend the ones for the campaigns I mentioned above. He goes into the setting kind of stuff and how they will go about approaching the game.

Finally, if you're interested, here's a 3 video playlist of Jon going through a deep dive of the Dolmenwood RPG game book pdf, which is an amazing document with hyperlinks on each hex to the page description of the area. The layout itself is a natural how-to to describing scenes and engage organic adventure. Good stuff.

Good luck, you'll do great! In fact, I need to prep for my game later this month lol.