I have been asked to shoot a small group (family, 12 persons). I have done some portrait stuff with one or two people with some success using a 580ex and 430 slave. I set up the my other stuff with the 580 mounted on the body and the 430 triggered at about 45 degrees to the subject using various angles for both flashes as well as stofens depending on ceiling height, ambient light, walls etc. My concern two fold:
Being able to cover the group with adequate light.
Posing for 12 person family.

Any ideas or links to the best flash set up and poses for a family would be appreciated. About the only thing I would be willing to pick up woud be an off shoe cord and another flash stand if that would help. This is not something I would do on a regular basis.

Thanks,

Rich

First question is the location. Natural light is your friend and may eliminate the need for flashes. If indoors at night, recommend a well lit area. Balance the ambient light with the flash by a combination of higher ISO and slower shutter speed (to record ambient) with the desired aperature (DOF and flash strength).
Merv

I hopefully will have quite a bit of natural light. There is a large window in the room I am shooting but I will have to check it out ahead of time.

Read this tutorial of mine which covers lighting / posing / technical considerations with group shots: LINK.

Putting the key light off to the side does not work well for groups due to fall-off across the group and the fact the the faces will all be oriented differently to the key light. A better strategy is Butterfly, in the generic sense of keep the key and fill centered directly over the lens of the camera. If there is low ceiling you could bounce one flash slightly off the ceiling as key light (no compelling need for the Stofen which will just cut power, using the second on the camera for fill.

Since you are using two flashes the StoFens are not an ideal choice of diffusion because they work by splitting each flash into bounce and direct components (see this tutorial on how diffuers work). Since you are using two flashes in a key / fill configuration you would have more control and better results with diffusers like these which bounce 100% of the flash output forward:

Thanks Chuck! Just what I was looking for.