You have two main 'driver' classes. CountFlips and coinWorth (may want rename this CoinWorth). You can only use one or the other. Whichever one you use, you need to instanciate some MonetaryCoin objects from inside your main. Then you will be able to call on their coinvalue() methods to load your coins[] array. Also you might want to put a constructor into MonetaryCoin. Maybe something like...

public MonetaryCoin ()
{
super();

// add your Random generator code here
}

Let me know if this helps...
Chris