For peninsular Spanish I would recommend "Assimil Spanish with Ease".
http://www.amazon.com/Spanish-Ease-L.../dp/2700510704
One thing I like about Assimil is that the audio is all in the target language. If you do the course as recommended by the publisher, you will have a very solid grounding in the language, or in other words, a good place to start with native materials.
Good luck