How to set different permissions on parts in N2 CMS admin?

Question

I have setup different users in N2 admin and different users should only be able to do certain things. For example, we should have just one sort of read-only user which can only read things but not edit anything. How to set up such in N2 admin area?

namespace N2.Security
{
  [Flags]
  public enum Permission
  {
    None = 0,
    Read = 1,
    Write = 2,
    Publish = 4,
    Administer = 8,
    ReadWrite = Write | Read,
    ReadWritePublish = ReadWrite | Publish,
    Full = ReadWritePublish | Administer,
  }
}