lovely list of 10 things you can do with chocolate ganache, complied by Hannah of A Very Foodly Diary. (This is a wonderful site, by the way!)
Here's my recipe for ganache. You can vary the amounts, depending on how much ganache you actually need.
Dark Chocolate Ganache
Yields about 3/4 cup
1/2 cup heavy cream
4 ounces bittersweet chocolate
Heat cream in a saucepan over medium heat. When cream is steaming (don't let it boil), remove from heat and stir in chocolate. Whisk mixture until all chocolate is melted and smooth (it will thicken as it is whisked).
Use as per recipe instructions. Or eat it straight out of the pot. You just can't go wrong.