Barron's MASTERING FRENCH GRAMMAR is an English translation of a French grammar and workbook originally written in French by Michael Deneux. The 233-page book contains chapters each dealing with a particular aspect of French grammar followed by exercises (for which there is a key at the back). It covers not only such elementary matters as word order, declension of adjectives, and the very complicated world of French verbs, but also more advanced concepts like arithmetic in French and stylistics.
I found this book extremely helpful in going from a passive understanding of written French, gained mainly by experience with Latin and other Romance languages, to being able to actively speak and write French. If you already have some knowledge of French and want to reach fluency, Barron's workbook is an economical way to do so and I do recommend it.
However, I wish that the authors had mentioned at least some pronunciation quirks (like the -Vnt ending of 3rd person plural verbs being silent). Also, there are some typos, and at two point a word is left in German from the original version, e.g "fabrikneu" to give the right sense of "nouveau" is left untranslated.