|Stuart hit the nail on the head. Most of us have taken post secondary education in order to do this stuff. This requires a significant expenditure of time and money. If you're sure you must have an Active Directory domain in your home you have three choices as I see it:|
1) Take training
2) Hire a professional consultant
3) Hope you can find someone qualified to do it for you for free
1 and 2 cost money. 3 is not likely to happen, especially on a forum like this since trying to tell you all you'd need to know by typing or talking on the phone is just not going to work. Therefore, you need a simpler solution and your best bet and would be to use a "workgroup" setup in your home.
In a workgroup environment users can still log into all the different computers. It's just that settings for each computer (wallpaper etc) will be unique to each device and will have to be setup manually on each different device. Also, if you save a file to your "My Documents" folder on computer A, it will not be available on Computer's B, C, D, E and F by default. But, if you were to spend a few $$$ on a home NAS, you could map a network drive inside each user's account to a share on the NAS that only they have access to. If everybody saves their files to the mapped network drive (and in turn, onto the NAS) this would make saved files available to each user from every computer and would also afford security (ie: nobody else but someone with administrator level access on the NAS could get into your personal data).
This would still require some learning on your part but would greatly simplify the process and reduce the amount of info you'd have to learn. The instructions on how to things on the NAS would come with the NAS for instance.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.