Electronic flash not only brings light to a photograph, it can be an important artistic tool?if you’ve acquired the knowledge to use it creatively. To master those skills, digital photographers need only turn to this complete reference. Packed with inspirational photos, it takes the mystery out of flash, covering every type of equipment and explaining such essentials as guide numbers, sync speeds, white balance, and more. Photographers will see how fill flash can decrease contrast and shadows in outdoor portrait photography, understand how to control the light using bounce and multiple flash techniques, and expertly employ high-speed and rear curtain synchronization to create impressive motion-blur images. Everything you need to know is here?including a section on studio flash and computer processing.
I found this book to be pretty helpful in understanding how to utilize my flash more. I think the author does a good job of being able to teach beginners and more advanced photographers alike.