Hola! I think that you know that I am teaching myself to speak Spanish, right? I discovered "Practice Makes Perfect" books through Amazon.com. I spent over a year and a half working through their (huge) basic grammar book, but although I feel that I learned a LOT, I do also think that every section could have gone more in depth with more exercises. Therefore, I have gotten some of their more topic specific books to find that depth. (Currently working on a book about the use of the subjunctive.) I think this particular book may be of interest to you:
http://www.amazon.com/Practice-Makes...2732432&sr=8-1
Enjoy!!