What this coin looks like (obverse, reverse, mint mark location, special features, etc.): One major variety is the 1830 "Small 0" Capped Bust Half Dollar. This variety features a smaller "0" in the 1830 date.
The difference between the small 0 vs large 0 can be distinguished by observing the size of the number. The small "0" is shorter and the spacing between the liberty bust and the number is much greater. The large "0" is noticeably taller than the rest of the numbers and there is less spacing between the liberty bust portrait and the number. The difference between the 1830 small "0" vs large "0" half dollar is depicted below in the example comparison image:
Coin value chart: Typical coin prices, values and worth in USD based on grade/condition