1) On Writing Well - William Zinser https://www.amazon.com/Writing-Well-30th-Anniversary-Nonfict...
2) On Writing - Stephen King- https://www.amazon.com/Writing-10th-Anniversary-Memoir-Craft...
3) The Elements of Style - Strunk & White - https://www.amazon.com/Elements-Style-Fourth-William-Strunk/...
The two most important points are concise style and active voice. Both of these habits are critical for SEs to write concise emails, specs and commit messages. You will even see improvement in more casual day to day interactions (via slack, SMS etc).
The second is On Writing Well. This book changed my view regarding how to write and how important it is to write well. As an engineer I regret how much I avoided writing in school. Now I play catchup after realizing lawyers and others with client facing jobs write much better emails. [http://amzn.to/2vTXu27]
And here are three other books that would be recommended by few on HN.
The Life-Changing Magic of Tidying Up: The Japanese Art of Decluttering and Organizing. I used to hate going home until I realized the clutter of stuff made me miserable.
Why Men Love Bitches. 100% serious. This book is over the top but I stopped being a doormat in relationships and looked for partners with more self confidence. [http://amzn.to/2wwcYeZ]
The Low Down on Going Down. Yes the title is cheesy, but again I am 100% serious. I think a lot of us have unhealthy expectations due to Internet porn and this book sets the right attitude for the physical component in a relationship.[http://amzn.to/2vTSY41]
And companion book: [http://amzn.to/2wwSpyY]
[edit: Hm, that might have been a bit optimistic, reading the article I clocked myself at ~420. I've never really tried to time myself on a dense paper -- say the first time I read Fielding's dissertation for example. I doubt I'd have read that at the same speed as a somewhat vapid article on speed reading (as the author suggest, although I'm a little taken aback that email is grouped with news as things not to read carefully -- I guess it's a sadly accurate picture of the current state of most peoples online discourse. Sinser would like a word with you! ;-)
 "Architectural Styles and
the Design of Network-based Software Architectures" (aka that ReST thing):
 "On Writing Well":
I'd say 1200 wpm is below skimming speed -- and there is something in-between -- but I'm not convinced that it's terribly useful as a skill. Being able to skim an article at great speed can be useful, for deciding if it's worth reading or not. I'm not convinced "speed reading" is very useful. The very term implies you speed through material at a speed greater than comprehension (which I'll loosely equate to "regular reading speed").
I do think it can be useful to train oneself to read faster -- by reading more, and occasionally by "forcing" oneself to read faster. For those that already read at reasonable speeds (~500 wpm?) -- it's probably useful to pick up tricks for skimming, and "backwards reading": starting with the conclusion, and reading articles backwards (conclusion, discussion, introduction -- or: conclusion, introduction, discussion -- and either way, probably conclusion again).