Some basics are in order... Not sure why you would buy speakers at all in the first place without asking at least a couple of questions first - especially if money is tight.
If you are looking to setup basic surround sound one of the best ways to do it is by purchasing a home theater in a box. These can be had for bottom of the line pricing under $200 - or even $100 and include all the basics to get you going including speakers, some sort of receiver, sometimes a cheap subwoofer, and maybe even a DVD player. The parts of the package...
1. The speakers - most people know that speakers are what make the sound you hear. But, in this world of computer speakers many people don't realize that speakers need power to operate and something to provide them sound to reproduce. Computer speakers often have built in amplifiers, typically in the subwoofer, and are they connect to your PC for sound. In a home setup, you want to be able to send TV audio, DVD, and perhaps other audio to the speakers so you need something to do this with...
2. Receiver: The receiver typically has audio and video inputs and allows you to connect different audio and video sources to it. A typical surround receiver will include at least 5 amplified audio channels of output and 1 subwoofer output to send a signal to a subwoofer. These days it is very common to see seven speaker outputs. The inputs for audio typically include a few digital audio inputs which can process surround sound audio for the 5 speakers and subwoofer (called a 5.1 setup). The processing of surround sound is a vital part of the operation of the receiver. It also controls volume to the speakers and provides POWER to the speakers so they can actually make sound.
3. The subwoofer is typically a self contained, powered unit that receives a low level signal from the receiver. It is designed to play the lowest frequencies of audio accurately. Not necessarily LOUD, but accuracy is key. Often people will not get a subwoofer because they don't want to annoy neighbors, but even a basic subwoofer, at lower volumes, is excellent for filling in the lower notes without irritating the neighbors.
4. DVD player? Yes, especially with cheaper systems, the DVD player is often built into the system to simplify connections.
IMO, you made a mistake getting those speakers without first figuring out what you wanted to do and then determining exactly what you needed to do it. At the better end of the basic level, a so-so home theater in a box may run $500 pretty easily. But, in your situation, what is it you WANT to achieve, and how much are you looking to spend to achieve it? If you have a TV already, you aren't necessarily going to get a huge upgrade by going with really REALLY bottom of the line surround as your 'upgrade' route.
