Google and free translations online are very very very inaccurate. I wouldn't recommend it if you are trying to be serious about learning the written language.

Why? Because they take short cuts and it's a computer generating what YOU wan't to hear. The computer doesn't know any better so it's guessing what you mean within your sentence structure..

So unless you wrote and spoke flawless textbook english...to the tee...I would definitely NOT use google cause you might end up with a broken sentence structure and get laughed at.

Yeah, I have the Japan Times grammar books. VERY detailed and useful. I also found one that's really good for quick reference, どんな時どう使う、日本語表現文型辞典（ひょうげん） （ぶんけい）（じてん）. Nowhere near as detailed however.

みんなのにほんご
 

Minna no Nihongo does come as paired sets, but it is designed for class-room use and for immersion teaching at that. I wouldn't recommend it for someone engaged in self study.

どんなときどう使う日本語表現文型辞典 does look promising though, and for a slightly more advanced student, 生きた”例文で学ぶ日本語表現文型辞典. A relatively raw beginner might be better served with マンガで学ぶ日本語会話術 though (it comes with a CD:url below) and seems to cover the basics very well. Each of the three has a precis available through google.co.jp -
mangademanabunihongokaiwajutsu

Not quite. You used the present (non-past) progressive form of 話す when you should have used the non-past form. You provided a translation for "I am speaking Japanese at school."

学校で日本語を話す = "I speak Japanese at school"