I'm attending a Japanese language school in Tokyo.
All the classes are in complete Japanese, so we have to learn all the grammar points using Japanese explanations. While it is very beneficial to do so, sometimes you just want to hear or see the explanation in English.
That's why I use
www.jgram.org
They are missing a few of the more colloquial grammar points, but for things that will appear on the exam, and most likely in your book, it's a great resource.
(Lol, I sound like a fake TV commercial.)