How do I simulate a login with RSpec?

I have been playing with Rails for a couple of years now and have produced a couple of passable apps that are in production. I've always avoided doing any testing though and I have decided to rectify that. I'm trying to write some tests for an app that I wrote for work that is already up and running but undergoing constant revision. I'm concerned that any changes will break things so I want to get some tests up and running. I've read the RSpec book, watched a few screencasts but am struggling to get started (it strikes me as the sort of thing you only understand once you've actually done it).

I'm trying to write what should be a simple test of my ReportsController. The problem with my app is that pretty much the entire thing sits behind an authentication layer. Nothing works if you're not logged in so I have to simulate a login before I can even send forth a simple get request (although I guess I should write some tests to make sure that nothing works without a login - I'll get to that later).

I've set up a testing environment with RSpec, Capybara, FactoryGirl and Guard (wasn't sure which tools to use so used Railscasts' suggestions). The way I've gone about writing my test so far is to create a user in FactoryGirl like so;

FactoryGirl.define do
  sequence(:email) {|n| "user#{n}@example.com"}
  sequence(:login) {|n| "user#{n}"}
  factory :user do
    email {FactoryGirl.generate :email}
    login {FactoryGirl.generate :login}
    password "abc"
    admin false
    first_name "Bob"
    last_name "Bobson"
  end
end

and then write my test like so;

require 'spec_helper'

describe ReportsController do
  describe "GET 'index'" do
    it "should be successful" do
      user = Factory(:user)
      visit login_path
      fill_in "login", :with => user.login
      fill_in "password", :with => user.password
      click_button "Log in"
      get 'index'
      response.should be_success
    end
  end
end
<