The following lesson should help you get familiarized with your instrument. By the end of this lesson, you should no longer need to use the word "thingy" to refer to the parts of your guitar ;)
An interesting fact about the Head-Stock is the variation in style you will find from brand to brand. Many guitar manufactures use the Head-Stock to brand their instruments. For example: the Cordoba Classical Guitar has a much more different head-stock design than that of a Vicente Tatay, and a Gibson has a much more different head-stock design than that of a Fender guitar. The Head-Stock is what helps keep the strings attached to the guitar. Within the head-stock you will notice at least 6 machine heads. These machine heads are also called tuners.
Tuners also come in different sizes and shape. Some are constructed using a combination of metal and plastic, while others are completely made out of metal. Quality tuners are a must in order to have a perfectly tuned guitar. This becomes much more critical when you are playing guitar with other instruments, as dissonance is more noticeable.
Considered as fret number 1, the nut plays an important role on the set-up of your guitar. Together with the bridge, the nut determines the separation between strings. Some of the materials used to construct this part of the guitar are metal, graphite, plastic and bone just to mention a few.
This part of the guitar seems to be straight a first look, but the truth is that the neck has a slight bow to accomodate for the tension generated by the strings. The neck houses the fretboard, frets and in many cases a rod of metal inside called a trus rod to help maintain the slight bow.
The top portion of the body of the guitar. It is amazing, but the sound board along with the body of the guitar serve as a natural amplifier. Together they amplify the vibrations of the strings to produce sound. In this case to produce a warm soothing sound that is characteristic of the classical guitars. Many guitar Luthiers, "guitar makers", spend years looking for the best or most exotic woods to use as soundboards. Soundboards are critical to the sound the guitar will produce once it is strummed.
The bridge helps tie down the strings. Perhaps most importantly, the bridge helps transmit string vibrations to the body and soundboard of the guitar. Bridges are made of almost the same material as the nut, with the exception of graphite.