The company i work for has an "annual meeting" in a few days, where all our franchises come together and we make a big day of it (around 400 people). I've been asked to do the photography for it. I'm no pro.. just an enthusiast.

Basically, was wondering if someone could help me tweak the settings to get the best shots?

I've got the following equipment:
- Canon EOS 30D
- Canon EF-S 17-85mm IS

Most of the shots will be groups of about 3-10 people, so i planned to use A-DEP or Aperture Priority at around f/7.1 at ISO 400 with built-in flash. The environment will be a big room with a fair amount of light, and it is surrounded by large glass windows looking over a golf course. It's a day event.

Can anyone suggest any tweaks to my settings... or a complete re-think?

Thanks for any help