London literary agent Julian Friedmann's book "How to Make Money Scriptwriting" focusses on the real world realities of making a career as a scriptwriter.
Topics range from getting an agent (or how to get by without one) to negotiating with producers, and a helpful explanation of some of the standard agreements. There is a relatively small amount of literary theory about the need for writing to have emotional impact on audiences and so on. I also found this section helpful, because it is portrayed as being borne out by the author's actual experience rather than anything more abstract. If you are reading this review, you probably will have already had your share of literary theory so you will know what I mean.
The ambit of the book is perhaps not quite as narrow as the title suggests, and I worry that its directness might put off more gentler souls. A less engaging but more accurate title might be something like "The Business of Screenwriting". That would be my only criticism, and it's not much of one.
Invest in your screenwriting career by purchasing this book.