Once you know the basic chords, it might be easier to think of them the way the function inside a key. For example, when in the key of E, the E (I) is called the Tonic. It's what all the other chords want to get to—which is what helps give western music its sense of motion. The A (IV) in the key of E functions as the Subdominant—it's sort of a passive in-between, just as happy to continue forward, as to relax back to the Tonic. The Dominant is just what it sounds like: it leads you where it wants to go. In the key of E, that role is filled by the B (V), and will definitely make your brain want to get back to the Tonic! When you get more familiar with the chords, and want to sketch out a tune, try writing it as I-IV-V (or variations of that) instead of E-A-B. It will make it much easier to transpose when you find out your singer cannot sing in the original key!
Learn a D major. This chord only requires the bottom four strings. Place your index finger on the 3rd string, 2nd fret. Your ring finger then goes on the 2nd string, 3rd fret, and your middle finger is the 1st string, second fret. You'll form a little triangle shape. Only strum these three strings and the 4th string -- the open D -- to sound out the chord.
The shape of the neck (from a cross-sectional perspective) can also vary, from a gentle "C" curve to a more pronounced "V" curve. There are many different types of neck profiles available, giving the guitarist many options. Some aspects to consider in a guitar neck may be the overall width of the fretboard, scale (distance between the frets), the neck wood, the type of neck construction (for example, the neck may be glued in or bolted on), and the shape (profile) of the back of the neck. Other types of material used to make guitar necks are graphite (Steinberger guitars), aluminum (Kramer Guitars, Travis Bean and Veleno guitars), or carbon fiber (Modulus Guitars and ThreeGuitars). Double neck electric guitars have two necks, allowing the musician to quickly switch between guitar sounds.