Get some broad shots, and get some shots of people looking bored, or really into it, get some shots using depth of field, with all the people in a row. Variety. Don't use the flash, except maybe once or twice during a break (if they have one) If you have a fast prime, bring that! Get to the meeting early and make sure all the lights are on, and if it's light outside, open the blinds ever so slightly, but no so that the light will blind people facing the windows. Aim the blinds towards the ceiling for example... Small things like that add up!