Rog
You asked about videos. Most black powder sources carry them. You can find a two disk series on Muzzleloader building, in fact, I think there's more than one. Pistols are in there too, as well as the Jack Brooks discs on beginning carving and beginning engraving. I have yet to find a video I would NOT recommend. You get to see how it's actually done and, in the case of different craftsmen, the wide variations in technique and style. For me, actually seeing it is the key. I can read how to do it, but watching it done makes all the difference.
That's not to say the books aren't invaluable. I'm sure I've spent far more getting books and cds than I have on actual gun hardware. But that's my particular style and each of us has our own 'right' way to do things.
I tend to agree with the advice given here to keep the first one simple. All that engraving and carving is wonderful, but you are building a gun first and foremost. The pretty parts can wait till later.
Get the basics down first: inletting, cutting barrel channels and getting the trigger, lock and barrel into the right relationship. My favorite personal gun is a relatively plain Leman style, but beautifully laid out. Simple, elegant and accurate as heck. Whoever made it was a master.
And there is no reason you can't inlet a lock into a 2x4, just for practice. I save all kinds of small scrap, just to practice on. I prefer to work with actual hardwood, like maple and walnut, since pine just isn't the same. That is especially true working with the fancier woods, like tiger striped maple and birdseye. They are very demanding, and it's best to practice before you cut into an expensive stock.
Working on your drawing skills is great. If you can't draw it, you can't engrave it. And the relationships are exactly the same on paper as they are on that exorbitantly expensive piece of wood you just bought. Make your mistakes as cheap as possible!
At least, that's the way I do things. We all have our own style, and you need to find what works best for you. And the only way you can do that is by actually DOING it.
Hope this helps
David L