L.P. Geldart, R.E. Sheriff, and D.A. Keys, Applied Geophysics , Cambridge University Press, 1976. This is an encyclopedia for various techniques. A bit difficult to read. Dobrin, M., Introduction to Geophysical Prospecting , McGraw-Hill, 3rd Edition, 1973. Somewhat outdated but a classic.
Information is still accurate.
Grant, F.S., and G.F. West, Interpretation and Theory in Applied Geophysics . This book goes a little deeper into the theory behind the kind of techniques we will discuss. Stacy, F.D., Physics of the Earth, Wiley, 1977. A general geophysical theory book that can be used to shore up your background if need be. There are a several other books in Folsom that are somewhat provide a more elementary treatment of geophysical techniques.