I'm by no means that great at this but I've put them in my cars myself a few times now. There area few things that you're going to need for sure. Those things are the subs you would like, the box for the subs (I greatly prefer what's called a ported box), an amplifier to actually run the subs, an upgraded head unit, and the wires to tie everything together. There are so many choices for all of these. Subs There are 3 main sizes, 10", 12" and 15". The preference is completely up to the person. 15's make a lot more noise, but it is much less controlled. A friend of mine had 15's and the best way to explain it is that it vibrates EVERYTHING. They are more for noise than to enhance your audio. To me they are just kind of chaotic. You can also kind of feel/hear them inbetween hits, which I do not prefer. 12's are much more controlled and well balanced. These are more for your audio enhancement. Depending on what you get they are better at hitting the low's a little better than the 10's. They are not nearly as loud as the 12's, but the bass is much more controlled and precise. I cannot give too much input on 10's, but I am about to buy one in about a week. Boxes There are 2 main types of boxes, ported and sealed. Ported boxes are my preference by far. They have spaces (ports) that allow the air produced by your subs to escape rather than being trapped in the bow. To me it makes a much clearer sound. Sealed boxes are boxes that have no room for the air to escape. To me they are more of a muffled sound. Amps This one I am still getting the details down for so you might want to google more about this one. But mostly there are some important things here. RMS, Peak power, and ohm's are going to be the biggest things that you see for an amp, The power level minimums and maximums for these all depend on the subs you are getting and whether there are 1 or 2 of them. Like i said google will be able to help you way more with this than i can. A note i would like to add is there are a few things that amps could possibly come with. The ones that i have come with a slider to control the bass. It can increase and decrease the bass that your amp puts out. Another main one is a kill switch. This is for if you have to cut off the power to your subs you just hit the switch and the amp is immediately turned off. Head Unit This is what people will see first about your sound system. This is the main face of what your sound system is. There are 2 major types, everything else is a sub-category. You have your single-din and your double-sin. Your single din is your basic most common type of head unit that you are going to find. If you decide to get one of these, it will come with some sort of plastic harness to make sure that it fits into the dash where it does. The double-din are going to be your full touch screen ones. They will take up the entire allotted space and will always be that size. No harness needed for these. The website you order from will always give you the option to "see if this fits in your vehicle" never neglect this feature. Wires This one is pretty basic, people try and buy the wires separate, but honestly I just bought the kicker wire set and it saved me so much hassle. Let me know if you have any other questions, I'm sure there is a lot i forgot but we'll leave it at this breakdown for now!