These are the 15 basic dialog poses I have found work best for a starting library for dialog. I have a tutorial explaining how to create the shelf in Maya and utilize a dialog library to get the timing down for speaking shots. This library is in no way meant to replace facial animation, but to serve as a jumping off point to the get the timing right. After you create synced dialog, all of the fun parts of being an animator starts with emotional passes, fleshiness of the face and asymmetry.
Try and match these images or make some of your own to match these basic poses. Make sure you poses are created with the hardest inflection possible so you can back off the poses a bit if needed.