For more info on patch clamp technique one may read books, visit labs or check for other web contents. Here are some choices for reading material.

Books:

1. Kandel, Eric et.al. Principles of Neural Science. New York: McGraw-Hill, 2000.
2. Areles Molleman, Patch Clamping: An introductory Guide to Patch clamp electrophysiology. Wiley, 2003.

Journals:

1. Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ. (1981). "Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches". Pflügers Archiv European Journal of Physiology 391 (2): 85-100. doi:10.1007/BF00656997.
   http://www.springerlink.com/content/h348734770442854/.