This may be my shortest answer on here. I make the assumption that this is not a question of where do I get my ideas. So I will leave the whole voices in my head conversation for when somebody actually asks that.
Most of the time I just have the urge. When I do not I go on walks or to parks and/or graveyards. My muses are hard rock bands with female vocalists. This is a recent addition, though music has often played a part in the process. During these trips I listen to bands like that (though hard rock is not always necessary most of the bands fall into that category) and I feel that drive to sit down and write something. The passion, the beauty, the gentle savagery of the voices and instruments along with the endorphin rush inspire me to make my own art. They remind me that words are a powerful thing and hearing them used to create in a different format drives me to my own medium.
Now if you mean how do I get the inspiration for my stories... someone will have to ask that directly I guess.