Phonetics is the study of speech sounds, it investigates physical properties of the sound waves constituting the actual speech signal and (unsurprisingly) shares a great deal of notion and tools with standard Signal Processing. Computational phonetics is the design of algorithms implementing phonetic analysis methods.

The books that are shaping my early training as a phonetician/linguist :

• Initially: Quantitative Methods in Linguistics and Acoustic and Auditory Phonetics both by prof. Keith Johnson, as well as Analyzing Linguistic Data: A Practical Introduction to Statistics Using R by prof. Harald Baayen.
  
• On the second round: Introducing Speech and Language Processing by prof. John Coleman and the tiny Phonetics introduction by prof. Peter Roach.
  
• On the third (on-going and pretty lengthy probably) round: Speech and Language Processing by prof.'s Dan Jurafsky & James Martin and A Course In Phonetics by prof. Peter Ladefoged.

The people doing the dirty field work that provides me with heaps of beautiful data to play with : Institute of Linguistics, Academia Sinica and Phonetics Laboratory, University of Oxford

The software that makes my work possible : Praat (alongside GSL, Eigen, MATLAB and R)

The usual "dependent variable" of my work is : F0, the Fundamental Frequency that in physiological terms expresses how fast a person's vocal cords vibrate.