There is a lot of good you tube entertainment on shooting out there, most instructional, some dangerous. The best way to tell the difference is to read the instructional parts of the reloading manuals to understand what each step does and why. Follow mfgr (die, bullet and powder) data to make safe ammo. Be slow to go off the reservation on your own.
As a handloader since 1972, I can say that most You Tube videos regarding basic reloading instruction are quite useful and accurate. Of course, there are bound to be a few that are not.
Certainly you should learn from the reloading manuals first, but if a picture is worth a thousand words, then a video is worth 10,000 words.
When it comes to the fundamentals of die setup, scale, and powder measure use, then you can rely on the better sources like the examples that I offered above.
The best way to separate the wheat from the chaff is to watch many videos and compare them to what you already know.
However, when it comes to You Tube reloading powder and bullet data, you should rely on the manuals exclusively, until you have a lot amount of experience under your belt, and even then proceed with extreme caution.
Incidentally, it is the close up set up and explanation of the Lee Safety Scale in the videos above that made me a believer in this modest little scale, and made me change my mind about it.