too long

My web development experience has mostly been setting up a CMS like Wordpress or Drupal and creating custom themes. Actually work in server-size coding has been very minimal. I've played around with php a little, trying to mod off of phpBB and beginning to learn some MVC work with CodeIgniter. Overall, this seems like a pretty big step forward, but it's something I need (I think) to do for a project I am working on.

Essentially what I want to do is have a service like Twitter of Facebook (not in the social networking sense); a user is able to log into the site and perform various operations, while also being able to use an android application that supports limited operations.

After some Googling and reading articles on the internet, it appears REST is the way to go. But I can't quite seem to grasp some of the technical details. I understand how the HTTP Request/Response works, but I don't know how I can code everything server side so that visiting example.com/item/1 will bring up the details of item 1 in the browser and can also perform a GET Request in my Android app so it can grab the details from the database and display in on the site.

Any suggested readings or some tips on how to execute this?

You can implement this using MVC. By default, have the controller ask the model for the details of the item, then pass the info to the view. Repeat this process for each type of request you want to accept such as POST, PUT etc., where you define a new function in the controller, ask the model to perform the corresponding database action, and return the response to the view.

There is helpful tutorial for getting a REST server up and running using CodeIgniter here