What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
The 1958 Doubled Die Obverse is the rarest and most valuable DDO error of all of the Lincoln Wheat Cent (Penny) series. There are only a handful known to exist and the coins are best identified by the very clear doubling of the legend "IN GOD WE TRUST" and the doubling of the word "LIBERTY" on the front of the coin. In addition: the 1958 date is slightly doubled but not as prominent as the doubling of the words. These double die features can be seen in the example image of the coin above. Source of example image is courtesy of PCGS.
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD