For LEGO Black Friday 2012, Barnes & Nobles will be offering a 30% off one item coupon (works on LEGO). Valid November 23-25, instores only. They will also have a Buy 1 get 1 50% off educational toy promotion for Black Friday. Thanks to forum member loporjai2003 for the news.
Until December 2, you can get a free $10 gift card when you purchase a $75 B&N gift card. Thanks to forum member melsig for the news.
*You can also use coupon code T9P3E3W for online purchases. However, note that LEGO items do not qualify as they are excluded from any sort of promotional discount.