The nylon string acoustic guitar has a softer, mellower sound than the steel string guitar. Strangely, modern audiences can still be spellbound by the depth of feeling of a nylon string guitar. It's entirely up to you which one you choose to play. I could cite a list of artists who used either nylon or steel string for this or that record, and make a wild guess or two at why the artists made the choices they did, but the bottom line is that if you want a deep, quiet sound that doesn't compete with your singing, the nylon string guitar is the way to go.
When you go out to buy a guitar, go past the general music store and on to your local guitar dealer if you have one. That way you will have a guitar expert guiding you and not some dufus who only plays two-and-a-half chords. Don't let the guy in the store automatically steer you to the top-of-the-range guitars, and equally don't succumb to your inner cheapskate. Pick a guitar that you like the look, sound and feel of, then come down in price range if you really need to.
To get some idea of the range you could be looking at, the Alvarez Masterworks Series MC90 Classical Guitar, a more pricey instrument, has solid rosewood back and sides, western cedar top with precision scalloped bracing, mosaic rosette and gold tuning pegs with tortoise buttons and sells for over 0. The Alvarez Regent, a beginner's model, is about 0. Of course there are many grades of price and quality in between.
The kinds of music that the nylon string guitar was designed for are classical and flamenco music. Classical guitar music is classical music composed for other instruments but arranged for the guitar, and classical style pieces composed especially for the guitar or other stringed instruments. There is a wide repertoire of music composed in the medieval or renaissance eras for the vihuela or mandolin and arranged for the guitar which can be extremely enjoyable and satisfying to play.
Flamenco music is a folk music of Spain, and is usually comparatively technically advanced simply due to flamenco being a "flashy" kind of music. If you are interested in exploring either of these kinds of music I suggest you go to YouTube and check out the classical or flamenco guitar videos. John Williams (the British guitarist, not the Starwars guy) and Julian Bream are two obvious starting points for classical guitar. Paco De Lucia, Paco Pena and Sabicas will open your heart to flamenco.
We can't finish without mentioning the nylon string guitar-driven folk music boom of the 1960's which has given us a lot of great music which can be easily picked up by beginner guitarists. The music of Pete Seeger, Burl Ives, Joan Baez or The Kingston Trio still holds some interest for modern guitarists.
So that is an overview of the world of the nylon string guitar. I hope you have found something to spark your interest.
