Matt Byrnes leads the Venice Beach Screenwriters group, and he's written some good stuff on the screenwriting craft. In one recent article he talks about anticipation, and how to build it in your audience.
He also co-wrote an article in the winter ScriptWritersNetwork newsletter (a downloadable PDF) about organizing a staged reading of your script. Check out the ScriptWritersNetwork website, as well as Matt's own screenwriting site, InScreenwriting for info on the Venice Beach Screenwriters.
