First and foremost: nylon or steel strings? The type of music you want to learn and play makes a difference. Nylon string guitars are generally used for classical, flamenco and sometimes folk music. They are not as loud as steel string acoustics and they are almost always played with the fingers rather than with a pick. They produce a wonderful warm and intimate sound. In recent years the sound qualities of the classical guitar have been finding their way into pop and jazz as well. This has given rise to a newer kind of classical guitar called a “hybrid” or “crossover” guitar. This instrument features electronics, nylon strings and a neck and fingerboard that more closely resembles that of a steel string guitar.
Acoustic guitars - also referred to as “steel string” guitars - are louder, brighter and are great for strumming, picking, playing in a group and accompanying singing. Remember, you can’t put steel strings on a nylon string guitar and, though you can put nylon strings on an acoustic guitar, the resulting sound will be undesirable.
Different acoustic guitar body styles and shapes produce different kinds of sounds. One of the most popular steel string guitar styles is the large dreadnaught size. It produces a rich, loud, full-bodied voice that favors the lower end (bass) frequencies. Another popular size is the OM which stands for “orchestra model.” This style features a smaller body that for some players can be more comfortable to hold than larger sizes. The OM produces a more refined, balanced tone and is not as loud as the dreadnaught.
Some beginners are attracted to nylon string guitars because the strings are softer than metal and they’re concerned about sore fingertips. This shouldn’t be a consideration since a properly set up (adjusted) steel string guitar will be just about as easy to play, and callused fingertips are an asset to every guitarist. In addition, nylon string guitars usually have a wider fingerboard that may be challenging for some players.
Finally, talk to the folks at your local music shop. They can answer all your questions and help guide you to the perfect instrument.