Let me first apologize if this is not the correct group for the following topic. Perhaps it belongs in the General forum but I just did not know where else to discuss this concept.

I need to add the following feature to an existing website:

Allow 50 different users the ability to log in with a name and password
This login is to bring them to a read-only area where instructions, information, etc., will be waiting for them.
Since these instructions will be different and private for each individual, this is the reason I need to have 50 separate login/passwords.

From the web owner's side, I need a way that he can access this same setup (via his website) and enter the 50 different instructions, directions, etc.
The web owner is not particularly technical, so I cannot have him directly accessing the server, etc.
His access should be via website, similarly to the way the 50 users would access their instructions.

Can someone tell me what I looking for with type of setup?
Is this the type of thing that a database would be needed for?
Is that any pre-packaged or already available code that could give me the ability to do something as I have described?
I have access to the server and PHP is available (though I know nothing about it). Is a pre-packaged program available in that language for something as I have described?
I also have MySQL on the server (though I have never used it nor know much about that either).

Hopefully I've described the project clearly enough to perhaps get some guidance as to what I am looking for.
As noted I do not know about PHP or Databases in general, but if these approaches are the method(s) I need to do what I described, I can probably get help to assist me.
Thank you in advance for any help or guidance you may be able to offer.