My first play experience was with the downloadable PDF "A Day Late, A Shilling Short" in the support section of this website. Give it a dry run by yourself, and then try it out on your group. (You might grab the coach location card from Hammerzeit.) When I played we had a great GM who made it really dramatic, and we had a great time! The thing about the WFRP3 system: it is really, really fun to play.