...to create portraits, then here is a book that I can highly recommend: Professional Portrait Retouchihng Techniques for Professional Photographers Using Photoshop by Scott Kelby (Voices That Matter, New Riders, 2010)
http://www.amazon.com/Professional-Retouching-Techniques-Photographers-Photoshop/dp/0321725549/ref=sr_1_3?s=books&ie=UTF8&qid=1318218981&sr=1-3
One of the following pics is the original Kelby image that I downloaded from the web site pics that accompany the book. The other is one that I made from his original using just a few of Kelby's methods.
P.S. Apart from the downloadable practice images that go with the book, Kelby's web site also includes the following:
1) a downloadable check list of things to look for in a portrait
2) a number of eyelash brushes to go with the chapter on creating eyelases for clients