Leather working hobby

I'm sure some of you might have this as a hobby or more of a profession.

I'm pretty new to it as I haven't really done much at all yet, and I'm looking to create a sheath for a knife. Are there any good videos to watch before diving into it, or any articles that come to mind?

Think of this as a place to discuss this topic as I didn't see one posted yet. Any input will be helpful!