There are many different types of sound systems available in the market today, with each sound system uniquely attuned to the person buying it. You don't have to be a die-hard audiophile to understand the basics of sound and acoustics, all you need to know is how you want your speakers to sound, given the size and orientation of the room, as well as what type of use you will need it for, i.e., for a home theatre setup or for purely audio use only.
Basic speaker systems are set up with the budget conscious in mind. These systems typically have fewer components to further the budget-end of the equation, and getting the basic components only will enable you to save up and spend more on the more important parts of the system that you may need in the future. When building your basic speaker system, do not be lured by the thought that more speakers will always be better. Remember, you want to go for clarity, not just amplification. Cluttering your system with too many speakers will result in too many harmful interactions between those individual speakers. What's worse is, sound cancellation may occur, and you will not be getting enough value for your money. You can start with a basic set of components, normally 60 Hz for good tweeters and midrange speakers.
You will also want to buy a basic head unit, able to play your music in a variety of different formats. Choose wisely, since you will want a head unit that is very adaptable to different uses and needs.
The amplifier can also be considered as one of the main components of your speaker system. You will want to get a good amplifier that can take the load of having multiple speakers connected to it at varying sound levels. Remember - if you overload your amplifier, you will end up with a smoking crater that used to be the wiring of your amplifier. Be sure to compensate for the load that your speakers will take up by purchasing a good, stable amplifier with ample wattage.
Basic bass speaker systems are mainly dependent on the type of subwoofer you buy and the amplifier as well. In cases like this, be sure to buy a subwoofer that has a rich, deep "thump" to it, as this will become the basis for the thicker tones of your system. Again, be sure that the amplifier you buy will be able to take the wattage required by your subwoofer; otherwise you may end up with more problems than when you started.
Once you've got the basics of your speaker system down, try it out with different types of music. If this is a home-theater setup, try watching different types of movies and experimenting with the treble, bass and surround settings on your amplifier. Rearrange the speaker positions as needed, and try to listen to the acoustics in your room and how you can use these to your advantage. If you are setting up a car speaker system, take your system out for a spin and try out different types of music as well. While the area for moving speakers around is limited, you can use the amplifier and head unit to tweak your speaker system's settings as you see fit.