ACL and User grouping

Hi,

Am new to rails and somewhat to ruby. Am building an enterprise class
application where I need to group the users, and also define read-only,
read-write, etc access permissions to various.

  1. How do you go about it? Are there any tutorials that illustrate /
    demonstrate these things in RoR?
  2. What ruby gems are used in the process?

thanks so much!

For authorization I had use cancan before

There is also a railcast about this.

Hope it helps.