I believe choosing a guitar is a very personal thing. The most important aspect of choosing a guitar is not just it's sound, but also how it feels to you. One of the most important things for a beginner to look for when choosing a guitar is the action, because when you first begin to play, your fingers tend to get sore if the strings are too high. So the first step in choosing a guitar is to identifying the type of music that you're most interested in playing. The best way of choosing a guitar is going to a shop and playing the ones you like.
Guitar players' tastes in guitars are as varied as the number of guitar builders. Guitar necks are nearly always made from timber, although in the past manufacturers have experimented with alternative materials such as carbon fibre and even aluminium. Guitar amplifiers directly affect the tone depending on the age and type of speaker within it. Guitars are fine instruments and deserve the best care in the world, if you want it to look good at all times and sound great as well. It will make your sound better if your guitar is properly strung, you will get a longer natural sustain.
If you are a beginner, you probably are looking for a lower quality, lower priced instrument that is still worth the money and is a good beginning instrument. You could consider buying a second hand guitar, which you can find for half the price of a new one, but it is important that the guitar is playable. By buying used from a reputable dealer, you get a higher quality/easier playing instrument for a smaller price the only sacrifice you have to bear with is some scuffs, scratches, and maybe a chip or two. As the price of the guitar increases, you will find that the back and sides will also be built using solid wood rather than laminated plywood. Some unscrupulous individuals sell counterfeit versions of name-brand guitars at ridiculously low prices on the used market.
One option could be to get a cheap acoustic, learn a few things, see if you're passionate about the whole guitar thing and then you'll have a much better idea of what you really want as far as sound and style. If one guitar sounds better in one store but is more expensive than the same cheaper model in another store, go with the one that sounds better. Buying from private individuals can be cheaper but the options of free repair and warranty are devoid in this bargain. Too often cheap beginner guitars won't stay in tune, are hard to play and just don't sound very good. The cheapest isn't always the best bargain.