Public relations and promotion have a lot in common, although they're not necessarily the same thing. It really depends on the size of the organization doing the job, or having it done. When you're a lone operator or part of a small group, both fields will be part of the same things. Here we have links and other resources that are mostly from the point of view of larger entities. That's OK, because the principles are the same. You can get a lot of nuggets of great information by reading what the pros have to say! Many sites offer free newsletters.
Good, quick info on writing a press release from the paid PR service
Online Public Relations
A variety of media lists, reference and other resources. The link entitled “Thoughts as of______ (today’s date)” is interesting for getting a feel for the general climate in the PR world
Strategic Public Relations—“Things I’ve learned About PR”
The Zen of PR for the advanced marketer
Resources on public relations
PR secrets—a collection of articles on various topics
Some free, some paid resources
A Publicity Primer