I am occasionally asked for introductory MATLAB materials. The only posts I've written here which I'd consider "introductory" are somewhat specialized:
Basic Summary Statistics in MATLAB (Apr-13-2007)
Getting Data Into MATLAB Using textread (Apr-08-2007)
Statistical Data Management in MATLAB (Mar-26-2008)
Much broader tutorials can easily be found on-line using any search engine. Searching AllTheWeb for
... yields a number of likely prospects, including a nice clearinghouse of such information hosted by the MathWorks:
A number of very well-written introductions to MATLAB have been written, especially by university professors and graduate students. Try searching things like MATLAB tutorial. As always, I suggest including PDF or PPT to improve the quality of discovered documents.