These are things that all writers really should read.
Varieties of Insanity Known To Affect Writers. This is from one of the finest editors I know, and while it's slightly tongue in cheek, it's all true. These are the things that pass through the minds of all writers. You'll see yourself here, and your friends. It's OK.
Slushkiller This is the most helpful discussion I know of about rejections, how to read rejections, what rejections really tell us, and, most importantly, "the rough breakdown of manuscript characteristics, from most to least obvious rejections."
Common Misconceptions About Publishing from Charlie Stross. He's a fabulous SF writer, a genuine geek, and he thinks smartly about hard stuff. This is someone who has been able to make a living as a writer; he's been around publishing a long time, and he gets digital publishing too.
This is Nothing Like an Official FAQ from AW's own publishing and editing Absolute Sage HapiSofi. A collection of questions and answers about finding legitimate publishers and agents, what "independent publisher" means, avoiding the slush pile, the purported demise of publishing, paid reviews, etc. Just read it; this is wisdom from someone who has years of experience in editorial and production, both, in print and ebooks.
A Letter to Baby Author Me A thoughtful letter of advice from a multi-published novelist to her "new author" self; what she wishes she'd known then. This is really smart.
From Chuck Wendig: 25 Bad Writer Behaviors (Or, How Not to Act Like A Rabid Little Penmonkey in Public) This is not how you want to be, but it is the way a lot of writers behave. Don't be one of those writers.
From University of Chicago Press: "What do Publishers Do?" by William Germano