Like all British coins, the reigning monarch appears on the obverse (the 'heads' side). King George VI appears in our picture, but your coin might be different. Queen Elizabeth appears after 1952.
Except for the penny dated 1946, all Australian pennies in this series are worth face value or a just tad more. The 1942 specimen in our example might sell for $1 or $2 US dollars because it is in nice shape and has acquired some attractive blue toning. Some collectors (like me!) really enjoy toned coins and are willing to pay a little more to get them. But not much more. BTW, most collectors do *not* prefer toning.
So, Mike, since your coin is in average circulated condition, it is only worth a few cents. Why not use it to start a collection of Australian coins?
Now if you had a 1946 Australian penny, you have the *king* of the series. These coins catalog for $35 even in worn condition, and climb toward $200 in well preserved condition.