Best book for crash course in english grammar?

[Alex/Mugaaz]

Anyway there is a new job position at work that requires me to grammar nazi skills. I've never had schooling in English grammar due to moving around so often. I basically just wing it. I'm proficient at the language and have no problem spelling. I have problems with things like comma usage, colons, when to use apostrophes, or when to underline, do I put magazine article names in italics, pointing out what the subject is, etc.

So should I just go find an ACT book, or is there something better? I can memorize easily for the test, but I'd rather get a book that is designed well so I can learn this permanently. I don't want to forget it all again, which is what happened last time when I had to study this for the ACT.

(braces for people correcting the grammar in this post)