PR is a quite wide field. I personally have been multiple times on TV, radio and mainstream newspapers for the topic of Quantified Self.

One of the best books to read on PR is likely Trust Me I'm Lying by Ryan Holiday. Ryan Holiday is a nerd and was Director of Marketing for the clothing company American Apparel. He also did PR for a few authors such as Robert Greene and Tucker Max.

Even when you don't want to use some of the dark arts technqiues he writes about, reading his description of how US newsmedia works, is likely very useful.