Need advice on the lighting

[gandhi]

I have two 430 EX II and one 580 EX II. I use the 580 to trigger the two 430 EX. Recently I have purchased the umbrellas and stand. Do you think this combination is enough to take pics for a group fo 5 to 6 people? Also any suggestions on how to place the umbrellas near the subject for a good photo

[iND]

That set up is more than adequate for individuals or small groups.
Remember as you move your umbrellas back the drop off of light is dramatic.
I would recommend the one umbrella at 45 degrees and above the other as a fill light.
I would just go with ETTL
You can set your on camera as master (and it does not even have to fire). Then your can set the slaves as A B and set the ratio in the menu.
You did not say what camera you have.
Be sure to set your aperture to get adequate depth of field.
Watch for ambient light of different color especially if from above, can give your subjects red hair.
Stobist site is great if you need any videos.

[gandhi]

I have T1i, so I have to use the 580 EX on my camera to make the master and slave.
Can you please give the website of Stobist where I can get the videos?
I have prime lenses 24mm II, 50mm 1.8, 100mm IS USM and 135 mm

[iND]

http://strobist.blogspot.com/