Discover's cash-back bonus categories for 2013 are:
January - March: restaurants and movies
April - June: Spring style
July - September: Summer fun
October - December: Holiday shopping
It's worth noting that Discover's standard 1 percent earning rate only kicks in after you've spent $3,000 in annual purchases. Below that, you're only getting 0.25 percent, which is pretty mean. What's even more mean is that purchases you make in bonus categories don't count toward that $3K threshold.
Rewards credit cards and the golden rule
The golden rule, which applies during the holiday season and throughout the year, is not to use rewards credit cards unless you plan to pay down your balance very quickly. On average, they come with higher interest rates than non-rewards cards, and these can quickly eat up the benefits you may get from cash back, points and rewards. Instead, use low interest credit cards for purchases that are likely to take you a while to pay down.