Picking out a guitar is a lot of fun -- at least if you have enough money to buy the one you want. It's also difficult. It's even more difficult if you haven't bought a guitar before. When you buy your first guitar, you may not even know what kind of music you'll wind up playing, or whether you're going to play it enough to make it worth spending so much money.
Fortunately, guitars are relatively cheap compared to most other instruments, and there are a lot of good, inexpensive models out there. By comparison, try to buy a cheap bassoon sometime. You'll be grateful that you're a guitar player, I promise.
Here are some important things to keep in mind when you're buying a new guitar:
One of the first things to decide is whether you want an acoustic or an electric guitar. I recommend that beginning guitarists buy an acoustic first. The main reason for that is that it's harder than you think to get an electric guitar to sound good. The nicest guitar in the world won't sound good if you plug it into a cheap amplifier. It also won't sound the way you expect it to. Most of the electric guitars you hear in recorded music are being played through an effects box -- or, more likely, a whole rack of them. If you start with an electric guitar, you'll also need to buy effects and an amplifier, and that can get very expensive. If you're just starting out and you're not even sure you're going to keep playing, you shouldn't spend that kind of money.
When you buy an acoustic guitar, you don't have to worry about all those extras. You just have to worry about finding something that feels and sounds good. Keep in mind that you can always buy another guitar later. Once you've been playing for a while, you'll know a lot more about what you want, and you'll be able to choose more wisely. If you're really hung up on the idea of an electric guitar, though, Larry Lapierre has a lot of good advice on the subject.
If the guitar you buy doesn't feel good and sound good to you, you won't play it. I know many more people who have a guitar they never play than I do actual guitarists. That happens because a lot of people think, "Well, I don't know if I'll stick with this, so I won't buy a really good guitar." They buy the cheapest guitar they can find and think they're being practical. In reality, that's not practical at all. A cheap, badly made guitar is no fun to play. If a guitar is no fun to play, chances are very good that it will end up living in the back of your closet, right next to your lawn darts and your hula-hoop.
This doesn't mean you have to spend a lot of money. There are a lot of good, inexpensive guitars out there. The first guitar I picked out for myself was a no-name brand I've never seen before or since. It cost $99 new (1983 dollars), and I still play it more often than I play the $1200 guitar I bought for performing.
If you're worried that you won't get your money's worth, remember that if you buy a good guitar and you never play it, you can always sell it and get most of your money back.
The best way to find out what features and feel you like is to play as many guitars as you can get your hands on. Play your friends' guitars. Go to guitar shops and play everything there. Take notes. There are a lot of factors to consider.
Don't be swayed by popular brand names. Just because a guitar has a name you've heard of on it doesn't mean it's a good guitar. It also doesn't mean it's right for you. It's best not to go shopping with preconceived notions about which guitars are "the best." Every individual guitar is different. Martin is known for making some of the best acoustic guitars in the world, but I've played Martins that I wouldn't have paid $50 for. Every manufacturer turns out the occasional dud -- and the occasional gem. Don't be a snob and refuse to look at unknown brands. You might miss out on something special.
What is it made of? Some cheap guitars have tops made of plywood. You don't want that, because over the years the guitar will pull itself apart. (It also won't sound very good, since plywood isn't known for its fine resonant qualities.) For acoustic guitars, a spruce or cedar top is ideal. Most acoustics you see will use one of these two for the top. As long as it's real wood, though, if you like the sound, it's probably fine. The back, sides, and neck can be just about any solid wood; mahogany and curly maple are both popular and attractive.
Electric guitars can be made of almost anything, but again, avoid plywood. Very hard woods are better, both because they're more durable and because they'll improve the guitar's sustain. Good electric guitars are usually heavy as a result. Ash, maple, and walnut are all popular.
The fretboard is usually either rosewood or ebony. (Fender Guitars puts lacquered maple fretboards on many of its models, which seem to hold up well.) Ebony is preferable, because it's extremely hard and won't wear as easily, but rosewood is perfectly fine. If the fretboard has been painted or stained, it's probably bad news.
Is it well-made? Look carefully. The frets should be even, and none of them should stick out more than the others. Many acoustic guitars have binding around the edges of the body. That's a good sign, but it isn't strictly necessary. Run your hands all around the edges of the body. If it feels like the wood doesn't quite meet properly in some places, don't buy that guitar. Hold the guitar up and sight down the neck. The fretboard may be either flat or slightly curved side-to-side, but if it doesn't look even, the neck may be twisted or warped. (This is something you're more likely to find in used guitars than new ones.) From the side, the neck should look straight. The tuning machines should work smoothly. (That isn't a primary concern, since you can replace them easily, but it gives you a clue about how meticulous the manufacturer is.) On an electric guitar, all the switches and knobs should work smoothly.
Does it feel good? This is the most important consideration. It's even more important than the guitar's sound. A guitar sounds different from behind than it does to your audience anyway. The thing you'll be most aware of is how it feels.
Is the neck a comfortable width? Different guitars have necks of varying widths. Classical guitars have very wide necks. Electric guitars usually have narrow necks. Most steel-string guitars' necks are somewhere in between. If you have thick fingers, a wider neck will make it easier for you to play. If you have small hands, a narrow neck is more comfortable.
Are the strings at a comfortable height from the frets? This is called action. Most people prefer a guitar with "low action," meaning the strings are relatively close to the frets. Low action makes a guitar easier to play.
Is the body a comfortable size? This is something a lot of people overlook. Most steel-string acoustic guitars have what's called dreadnought style bodies. These are big guitars, and if you're a small person they can be quite uncomfortable to play. When you sit down with the guitar in a normal playing position, you should be able to reach the soundhole easily, without having to stretch. If it's even a little uncomfortable, it will affect your playing. People play best when they're relaxed and comfortable. If the dreadnought body is a problem for you, consider a smaller guitar.
If it's an electric or acoustic/electric guitar, are the controls in a convenient place? Some guitar makers put controls in places where you might accidentally hit them while you're playing.
Does it sound good? Have someone else (a salesperson or a friend) play the guitar for you. Just because it sounds good to you when you play it doesn't mean it will sound good to your audience. What "sounds good" means is subjective, of course. If you like the sound, it sounds good.