When I was in college, my beloved advisor and mentor, Dr. Sam Longmire, one day handed me a copy of Strunk and White's The Elements of Style. "Read it," he said, "and take it to heart."
Arrogant college student that I was, I don't think I read it right away. But a few years later when I faced taking Macmillan's pre-employment editing test, I decided to break it out and see whether I could learn anything quickly.
To my great surprise, it was a good read. It was quick (less than 100 short pages), easy to grasp, and interesting. It all made good sense and I did indeed take it to heart.
A few days later as I sat in the conference room with the editing test in front of me, I was delighted to see that several of the errors on the test came straight from the book. Had I not read it the night before, I probably would have missed those.
So, you know the rest of the story. I passed the test and got the job. Eight years later when I faced the JIST editing test, I again broke out that little book and again found it directly useful.
I think you know where I'm going with this. Read it and take it to heart. You won't regret it.