For my own videos, I use a few rules of thumb to answer questions like this: Assume players know how vanilla Minecraft works already, and that they have at least a passing familiarity with the most common mods. Don't be too repetitive, and don't hesitate to cut the video if you have nothing to say and aren't doing anything new. Have a goal (or multiple goals) for each episode, of an appropriate size that allows you to get them done in half an hour/45 minutes/however long you want your episodes to be.
My first episode went like this: Start a world with a random seed. Goal is to find a forest biome, build a simple home in it, and build some sort of machine for ore doubling. I started in an enormous Ice Plains biome and had to walk ~2000 blocks from spawn to find the location I wanted. I showed a few quick clips of starting out and surviving the journey, but didn't spend much of the episode on it. Once I found my location, I did a montage of clearing out trees and building my starter home, then a few clips of caving, and spent the rest of the time crafting machinery. It went pretty well, but if I did it again today, I would try to find a way to cut it up less, and have more time during the episode where I can talk continuously while doing something interesting. There's such a thing as too much talking, but there's also such a thing as too little.
Some other tips, in case you're interested (feel free to ignore and do your own thing): Use a stopwatch to keep track of how long you've been recording, pausing it when you intend to cut a part of the video out. Invest in a high quality microphone, not just a cheap headset - the Audio-Technica AT2020 USB works great for me. Speak loudly and clearly and get a feel for how you'd like to sound on your audio recording. Be honest, and be yourself; it's easier to relate to a real human being who acts like one than someone playing a character.
Good luck!
My first episode went like this: Start a world with a random seed. Goal is to find a forest biome, build a simple home in it, and build some sort of machine for ore doubling. I started in an enormous Ice Plains biome and had to walk ~2000 blocks from spawn to find the location I wanted. I showed a few quick clips of starting out and surviving the journey, but didn't spend much of the episode on it. Once I found my location, I did a montage of clearing out trees and building my starter home, then a few clips of caving, and spent the rest of the time crafting machinery. It went pretty well, but if I did it again today, I would try to find a way to cut it up less, and have more time during the episode where I can talk continuously while doing something interesting. There's such a thing as too much talking, but there's also such a thing as too little.
Some other tips, in case you're interested (feel free to ignore and do your own thing): Use a stopwatch to keep track of how long you've been recording, pausing it when you intend to cut a part of the video out. Invest in a high quality microphone, not just a cheap headset - the Audio-Technica AT2020 USB works great for me. Speak loudly and clearly and get a feel for how you'd like to sound on your audio recording. Be honest, and be yourself; it's easier to relate to a real human being who acts like one than someone playing a character.
Good luck!