The neck obviously must be made of a very hard material to withstand the pull of the strings and to remain stiff instead of vibrating with the strings. The neck can't be too stiff, however, or else it will have no room for adjustment. Most guitar necks require a little bit of forward bow in order to minimise fret buzz. Most guitar necks are made out of Maple, which is very hard wood.

The nut is where the strings meet with the neck and then pass through to the tuning machines. This is one of the two (make that 22 - 26) places where your strings physically connect with the guitar and transfer energy into it. Obviously the characteristics of these points are very important to a guitar's tone. You want your nut to consist of a very dense, hard material like bone.

Many cheap guitars have plasticnuts which absorb a lot of energy without passing it along to the rest of the guitar. They kill attack and sustain as well as dampen high frequencies. Bone is one of the prefered materials because it is strong but easy to shape. Metal is hard to work with but gives a very intense attack and boosted high frequencies to the guitar. Corian is a synthetic material often substituted for bone; I've used it on a few guitars before and it has very similar characteristics.

It's important to note that the nut is only noticabley affecting a guitar's tone while an open string is played. When fretted, the vibration of the string doesn't travel along to the nut.

Try this >> pluck your low E string and touch the very top of your headstock. Now fret the low E at the seventh fret, pluck the string and feel the top of your headstock. Do the same at the 12th fret. You should notice that the vibrations you feel in your headstock decrease as you play further up the neck. This occurs since the source of the vibration is moving further from the headstock and closer to the body. Therefore neck has less of a tonal effect the higher you play on the fretboard.

When you are fretting a note, that fret takes on the role of the nut. 99.99% of frets are metal, although I've seen a guitar that has a ramped fretboard instead of frets and there are plenty of fretless guitars and basses out there. If the frets on a guitar are worn down or not well levelled and crowned (round) they can produce buzz and other unwanted noises, mess up the guitar's intonation and require a higher action. Keeping frets level, crowned and clean will keep your guitar in tune and your bends smooth and juicy.

Tuning machines affect how well your guitar stays in tune.

The wood used as the fret board is often cited as having a strong effect on the attack and sustain of a guitar. Rosewood and Ebony are the most common fretboard materials. Many Fenders don't have a separate piece of wood as a fretboard, instead seating the frets right into the Maple neck. I'm told that Rosewood is "creamy", while Ebony has a sharper attack and more high frequencies. I like Rosewood fretboards because I like the look of the wood.

The way a guitar's neck is attached to its body is crucial to how well the guitar resonates. There are many ways to attach the neck, but the most important requirement for all is that the join be strong.

Bolt On Necks were pioneered by Leo Fender and use four screws (not bolts) to hold the neck in a well-shaped pocket in the body. I've read that this enhances the guitars high frequencies.

Set Necks were chosen for Gibson guitars like the Les Paul. They work by permanently affixing the neck to the body with glue. This is how most acoustic guitar necks are attached.

Neck Through guitars have the wood the neck is made from extend all the way through the base of the guitar. This join supposedly boosts mid-range frequencies of a guitar's tone.