- Do a search on each big blog for "why I hate PR people" and learn from those mistakes (there is an infamous one on TechCrunch from Arrington)

- If you want to learn the basics just get a book like "PR for Dummies" to learn the 101

- In my own experience with PR you need to care about results: If that's the case unless you are willing to invest the time and have the skills there is actual value to hiring a PR pro. If you look at Apple back in the day Regis McKenna really helped to put them on the map (http://www.regis.com). When you hire a good PR person what they bring to the table is a good rolodex, not the ability to pump out press releases and the like. The rolodex and the doors that open are what you're paying for IMHO.