managing author's permissions

Hi all!

I’m building a new site and would like to add author-users, but I want them not to have any permissions but only writing one single post (or to control the number of posts they can write).

Morover I don’t want them to see the whole posts lists.

I was thinking maybe there’s a way that I can create the post and to set its category, and only to give the user the permission to edit this specific post.

I apreciate any ideas / help / plugin recommendations.

Thanks ??