I am photographing a group of 5-7 Moms and their infants. I have a Canon EOS 20D, with the following lenses: 50 1.4 and 100 2.8; for flash I have the 580 EX Speedlite. Any suggestions on manual settings I can/should use would be appreciated. I am fairly new to this so feel free to be as specific as possible! 
I will likely be inside with only the flash and the natural light or (hopefully) outside.
Thanks,
Steph


