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

Books: 

1. Martin, Rosemary. Neuroscience Methods. Chur: Harwood Academic, 1997.
2. Bertil Hille .Ionic channels of excitable membrane,2nd Ed. Sinauer Associates Inc, Sunderland, Massachusetts,1992.
3. Kandel,ER.,J.H.Schwartz and T.M.Jessell.Principles of neural science,4thEd. McGraw-Hill Companies, Inc , New York, 2000.
   
    

Journals:

1. Cole, K.S. (1949) Dynamic electrical characteristics of the squid axon membrane. Arch. Sci. Phtsiol.3:253-25.
2. Hodgkin, A.L. & Huxley, A.F. (1952a). Currents carried by the sodium and potassium ion through the membrane of the giant axon of Loligo. J. Physiol. 116(4): 449-472.
3. Hodgkin, A.L. & Huxley, A.F. (1952c). The dual effect of membrane potential on sodium conductance in the giant axon of Loligo. J. Physiol. 116(4): 497-506.
4. Hodgkin, A.L. & Huxley, A.F. (1952e). Propagation of electrical signals along giant nerve fibers. Proc R Soc Lond B Biol Sci. 140(899): 177-183.
5. Hodgkin, AL, Katz, B. The effect of sodium ions on the electrical activity of the giant axon of the squid. J Physiol (Lond) 108,37–77,1949.
    

Webilography:

1. http://vlab.amrita.edu/index.php?sub=3&brch=212&sim=768&cnt=1