Being active on social networks before, during, and after your event is a no longer an option but is now expected by the attendees. Since events are in real time, attendees often use social networks to get updates and to engage with other participants in a live environment. The most important part of your strategy is going to be the planning.
We have put together a sample checklist to help you prepare for the cornucopia of opportunities that events open up to a Social Media Manager. No need to take notes, this one is pulled directly from our Definitive Guide to Event Marketing: http://bit.ly/dg2-em