On-Camera Flash by Neil can Niekerk

This book is about learning how to use your speedlite to its fullest to create great looking portraits. He covers what options there are for speedlite modifiers, what camera settings and what flash settings to use and different lighting techniques. He then gives a variety of example situations and how to achieve the lighting you want. A good book to get you comfortable with your speedlite.

Find it here:
Amherst Media
Amazon
Barnes & Noble