Buy some chewable Pepto Bismal to keep in your pocket, never be afraid to say "I don't know" or "Can I get back to you on that, I'll have to look it up." Preceptors ask questions to draw you out, not to expose lack of knowledge. You'll surprise yourself just how much you do know. I'm sure you'll pick up on things that aren't being done the "right way"! Students/New Grads are pretty well versed on Evidence-Based Practice!