Best way to get to get touch inputs?

The Unity "Input" class handles touch: http://docs.unity3d.com/Documentation/Manual/Input.html.

To make things simpler, there are also touch libraries in the asset store. We use "FingerGestures", and are happy with it.

There is also a great iOS tutorial that leads you through many aspects of programming including touch: http://unity3d.com/support/resources/tutorials/penelope.