If you're a public relations beginner, be sure to check out the entire Guide to PR by Brownstein & Egusa. And for some more detail on PR strategies, be sure to read the guest post – PR Advice From A Former VentureBeat Writer – from Conrad Egusa on Scott Monty's fantastic blog. Special thanks to Marty Thompson for the find!
If I were going to add anything, it would be a step somewhere between 3 and 4 when you actually define your pitch. I have several PR representatives that I'm on a first name basis with… and one is an author on our blog with permission to share whatever information she wishes. The reason is because the author fully respects the mission of our blog and never abuses it. Having a fantastic, personalized pitch is essential!