Not a writer, but I do sometime read Terresa Nielsen Hayden's Blog http://nielsenhayden.com/makinglight . She is an editor, and she does often write about that job. The comments she gets are also often interesting too.
Here is one essay, that I found searching the site, about rejections for example.
http://nielsenhayden.com/makinglight/archives/004641.html
And at last a link to a link page about publishing and writing
http://stephanieleary.net/article/510#comments