Choosing a new guitar, regardless of your ability or experience, is never an easy task. You must always consider the type of sound you wish to create, your maximum budget and the style of music you're learning to play.
The three most common types of guitar are categorized by the material their strings are made from and their status as electric or acoustic. Therefore, you may either want a Nylon-stringed acoustic, a Steel-stringed acoustic or a Steel-stringed electric. Each of these is distinctly different and will be better suited you different styles.
Nylon-stringed acoustic guitars tend to be the cheapest variety and are the easiest to learn on because of the extra space between strings and their relative kindness to fingertips. Typically, they are used either as beginner instruments or for travel purposes where there is a risk a more expensive instrument may be damaged.
Steel-stringed acoustic guitars are similar in construction to their Nylon-stringed counterparts, but are generally used by more serious or professional players because of their usefulness in building playing-endurance and finger strength. These instruments are of a mid-range price and are also available in electro-acoustic varieties.
Steel-stringed electric guitars are distinctive because of the presence of a pickup (which turns vibrations in the strings into electrical signals to be emitted by an amplifier) and the absence of a hole in the body (which the pickup renders obsolete). Electrical guitars are the most versatile types and thus, the most expensive. Whilst you may pick up a budget electric guitar fairly cheap, this is useless without the concurrent purchase of an amplifier, which again varies in quality and price.
When buying a guitar, it is always best to have an impartial, experienced player with you in the store. If this is not possible, research the meanings of build-quality, neck-relief and intonation with reference to guitars and be sure to look out for each.