I have a Canon 430EX external flash. I have had it for at least 3 years and I am still clueless on how to use it. I have read the manual a few times. But I honestly don't know what a lot of it means or how to use it. I shoot mainly in manual, but I can change for the flash if needed. I just can't get a good picture when I use it. I guess what I need is a flash course for dummies. Can anyone help? Or isthere a good book that can help those like me? The manual talks about high speed sync and second curtain sync and ZOOM. How do I know when to use these? Or to use one or the other all the time when using the flash.