This is an excellent secondary text for an intermediate student of Arabic. I wouldn't try to teach myself grammar points out of this book, but it is a perfect reference guide for refreshing knowledge of the more subtle points of fusha grammar.
Grammar points are explained in English with English terms. The Arabic grammatical terms are in parenthesis following the English. Thus this text will not help you understand 'irab like the Arabs do- for that you'll have to tackle something like the al-Jurumiyya. In lieu of something that hard core, Haywood and Nahmad have created a quick and relatively painless reference guide (far more user friendly, if more modern-focused, than Wright's Grammar).