A mandatory link for this subject is precisely OSDev
. You may want to carefully read most of its articles to get a clear idea of what you're against.
I would say that a "normal user" has NO chance of coming even close to a "hello world" OS developement
The thing is, operating system development is probably the single most difficult experience in the programming world. If you have considerable
experience in general programming, you might attempt to learn a bit of it and over time get to some more concrete result, but without development experience I would suggest to begin by something more simple and mundane.
Once you grasp the concepts and basic inner working of a computer it's a nice project to undertake, but take into account that's not easy at all. It could be very rewarding once you get something decent in place, though.