I am completely audio illiterate. How would I go about installing an enclosed subwoofer into my new Accord coupe?

 

Step 1: Getting clean pre-amp signal from stock head-unit
Step 2: Equipment to purchase.. your budget. Amp kit, Amp, Sub(s), and Sub box
Step 3: Sound deadener (your choice)
Step 4: Installation (get it done by shop or tackle it on your own)

These are the overall general steps.. someone else will fill in the details