Unless it is a client based game where nothing is stored between sessions, you will also need a web server with a database system and a server side scripting system. In the past, I have used Apache, PHP and MySQL, but that is starting to be quite a while ago, so have a look around.
Other buzzwords you may have a look into is JSON, JQuery.
Security is a must, so make sure you understand the dangers and pitfalls of a poorly designed system for handling logins and sessions (how you store your passwords, for instance), and data that is sent to the server from the client (it can not be trusted without validation), and SQL security as well (SQL injection, for instance).
All these suggestions are based on what you mentioned in your original post, and there are other choices you can make too, like scrapping everything mentioned above and go for something like FLASH, for instance, client side. You will still need what I mentioned on the server side if you want persistence.