Professor Downey's book looks really good. I learned most of my MATLAB by using the following book, which was prescribed to us in Purdue's Freshman Engineering at the time:
http://www.amazon.com/MATLAB-Introdu...mm_pap_title_2
However, I would suggest Professor Downey's book over it. If you are looking for lots of examples and exercises, Cleve Moler (one of the authors of LINPACK and EISPACK, and perhaps more importantly today the inventor of MATLAB) has two books for that:
http://www.mathworks.com/moler/
Hope that helps.