If you ever need a great online chord finder check out All Guitar Chords on the internet. In addition to guitar chords they  have guitar scales, chord progressions, arpeggios, reverse scales, scales to chords, chords to scales, licks, and many other features. They advertise having approximately 2000 chords and 86 scales.

As a beginning player I found this site very useful.

JR

Below I have tried to make an informative organization of the Types of Guitars there are, and a short description of each. As far as I know there is not a formal classification set up like plants and animals are in Biology by species and genus.

Shown below I have divided guitars into two classes each of which have different types of guitars.

Acoustic

The acoustic class of guitar is made to generate enough volume to be heard in close quarters and small rooms. It is primarily used by folk and country and western singers these days. Some accoutic guitars make beautiful sounds.

Acoustic Drednought 6 and 12 string

The Drednought type of guitar was first brought to market by CF Martin Co. in very early 1900s. This type of guitar is what is thought of in modern days as an acoustic guitar to most people. The 6 string Drednought is the most popular acoustic guitar of today. While the 12 string is very seldom seen.

Acoustic Cutaway Drednought

 This type of guitar is actually a later version of the acoustic guitar above. A portion of the neck end of the body was cut away to allow the player to easily get their fingers to the higher frets on the guitar.

Acoustic Parlor

The type of guitar classed as parlor were primarily used in the days before music was recorded. This type of guitar has a small body even smaller than that of a Classical Acoustic. The neck of a Parlor guitar is wider than that of the Drednought. Finger style players often prefer Parlor guitars.

Acoustic Classical

The Classical type of acoustic guitars have a smaller body than that of a Drednought and a wider neck and a flat finger board. The most noticible difference in this type of guitar is the type of strings used. The Classical guitar uses nylon strings. In the past cat gut strings were used on these guitars.

Acoustic Bass

Bass guitars are usually larger and longer than a regular Drednought. This type of guitar has four or six strings with four string bass being the most popular. Accoustic Bass guitars are seldomly seen today.

Acoustic Resonator    

The resonator or res phonic guitars are a type of guitar which have a metal plate on and around the sound hole of the guitar to help resonate the sound outward. Today these are rare and are used mostly by Bluegrass and Country Blues musicians.        

Electric

The electric guitar requires an amplifier to be heard at any distance. The invention of the electric guitar made it possible to play modern music in front of large crowds. Amplifiers allowed the volume to be increased and adjusted between players and instruments changing both tone, pitch and frequencies in some cases so that bands could make distinctive sounds.

Electric Acoustic

The electric acoustic guitar of today is usually a Drednought type of guitar with electric pickups installed. These are some time used by modern day country and western musicians.

Electric Hollow-body

This type of guitar is an electric guitar that has a hollow body with special shaped sound holes. They make a special sonic resonance that blues and jazz musicians like.    

Electric Solid-body

This is the most popular type of electric guitar used today. Both Rock and Roll and Country musicians use this guitar. These guitars along with their amplifiers give the musician the most options to work with to both mimic and to create new sounds.

Electric Bass

Almost every modern day band that has an electric guitar in it also has an electric bass guitar player. This type of guitar complements the solid body guitar and helps to deliver the rhythm of the music.

Electric Lap Steel

While the earliest types of these guitars were actually acoustic. Since the 1930s they have been primarily electric which is why I classed them under electric guitars. These are different from all other guitars above as they are not played by pressing a string against a fret, but buy sliding a steel bar across the strings making a special sound. The name lap is because they are held in the lap of the player.

Electric Pedal Steel

 This type of guitar has evolved from the Lap Steel guitar. It is built in a console and stands on legs like a small organ. There are pedals also attached that the player can use to produce different sounds.