Speaking before a group is always a little nerve-wrecking. If you don't get nervous you may not be challenging yourself to tell folks about new and challenging things. Biggest things I think I like to see as an audience member: Be enthusiastic, don't sweat the small stuff, be open to questions and discussion, don't pretend to know everything - you don't, and we (the audience) know it. If you have a passion and fire about what you're presenting, that attitude will be infectious!