I have been using Gramática de uso del español, Teoría y práctica for a few weeks now and I find it to be a really good book. There are different books for the different levels of Spanish. There are 106 lessons in the book I chose. Each lesson is 1 page of theory followed by 1 page of exercises. Solutions are included at the back of the book. I found it on Amazon & like it a lot.
Lo más importante es tomar en cuenta los acentos, ya que el quitar o agregar y el lugar que ocupa en la palabra, puede cambiar el significado de la misma, así como, los sinónimos, antónimos y homónimos, lo cual hace que cambie el sentido de la oración.
I bought 'Schaum's outlines Spanish Grammar 4th Edition' and 'Practice Makes Perfect: Advanced Spanish Grammar.' I've only made it through the first few chapters of 'Advanced Spanish Grammar,' but I would recommed both books to anyone learning Spanish. The only problem is the sheer volume of new information; it's impossible to retain it all. I would imagine you'd still be picking up new things on your 4th or 5th reading of them.
Schaum's has a particularly useful section on the subjunctive as well.