Orin Kerr, professor and blogger on the popular blog, The Volokh Conspiracy, has written an article with advice to 1Ls on how to handle being called on by law professors.  Entitled, "What to do if you don't know the answer", Kerr offers some valuable advice for the nascent law student.

Advice for 1Ls: What to do if you don't know the answer -- The Volokh Conspiracy