Lincoln Bicentennial Cent
The familiar Lincoln portrait facing right with IN GOD WE TRUST, LIBERTY, and the date 2009. One of four designs telling Lincoln's life story: a log cabin (birthplace), young Lincoln reading on a log (formative years), Lincoln before the Illinois capitol (professional life), and the half-finished U.S. Capitol dome (presidency).
Composition
Key dates to look for
2009 Bicentennial Cent
Face value worn; $1 – $10 for crisp uncirculated examplesAll four designs had unusually low mintages for a modern cent — worth saving in high grade
2009-S Bicentennial Cent
$3 – $10 per coinProof-only issue found in 2009 proof sets, with mirror-like fields
Valuable varieties & errors
2009 Formative Years Doubled Die Reverse ('Extra Finger')
scarceDozens of doubled reverse dies are documented on the Philadelphia 'Formative Years' design showing young Lincoln reading on a log. The best-known versions appear to give Lincoln an extra finger or doubled thumb on his hand.
2009-D Formative Years Doubled Die Reverse
scarceDenver produced its own batch of doubled reverse dies on the same log-reading design. They are generally a bit scarcer than the Philadelphia versions.
Error types found on this series

Doubled Die (Reverse)
Same as a doubled die obverse, but the doubling appears on the back of the coin.

Off-Center Strike
The blank wasn't centered when struck, so part of the design is missing and part of the coin is blank.

Grease-Filled Die (Struck Through Grease)
Grease and debris packed into the die's recesses blocked part of the design, leaving weak or missing details.
Machine Doubling
The die bounced or chattered at the moment of striking, smearing a flat shelf-like second edge onto the design.

Die Crack
A crack in the die fills with metal during the strike, leaving a thin raised line on the coin.
Real photos where available (credits); others are illustrations.