The distinctive star differentiates these coins from Ghana from later issues, which show (for many of them) cocoa beans and use the 'pesewas' denomination.
Like all modern coins, these are worth very little because they are made of non-precious metal. The half penny and penny are made of bronze and the pence and shilling are made of copper-nickel. A collector might pay a few US dollars to add an uncirculated specimen to his or her collection.
There is an exception: the 10 shilling coin is made of sterling silver, with 0.841 troy ounces of the precious metal. This coin is worth its weight in silver. Look up silver values at kitco.com.