I'm very confused about how to do a game work in a browser like monopoly, backgammon, etc. I have knowledge in html, css, php, and my question is what should I start to study/learn to make a game play with anothers on the web, I think what I should start to learn is AJAX, but what else? How can I do the game? How should I arrange the mysql database info for the game... any tips is appreciated. Thanks.
A basic requirement would certainly be Javascript. That's what the "J" in AJAX actually means. You basically need two things: the client-side code dealing with the user input, sending requests to the server, dealing with the responses, managing all the graphics; and the server-side system handling requests triggered by the client code and providing adequate responses. How you should "do the game" and "arrange" the MySQL database strictly depends on the game you want to create. Of course your request is too generic to be able to provide you any meaningful help.