Like I said in my previous post, I decided to pursue my idea of Project J.
I said I was going to use Node.JS but eventually I picked a less difficult path and continue with PHP.
Through the subreddit /r/webdev on reddit.com I discovered a nice course containing everything I needed to get to my goal.
The course is on Udemy.com and it's called Building an instant update database interface with jQuery/AJAX
So far, so good, because of all tuts and courses I saw/read/learned, this one is by far the best. Big kudos to Richard!
More to come later.