I might be getting my first car soon, and I definitely want to put my own sound system in. However I do not know anything about car audio systems. Now I'm not asking for you to tell me all the sound information, I am asking a simple question and do not want a lecture as an answer. I will likely have a mid-size sedan (about the size of a Camry or the like). I do not want really heavy bass (just moderate bass). I want a more clean/crisp sound (that you can hear the lyrics without excessive vibration) with about medium bass. I want it to turn heads of course and be impressive, but I'm not asking for a setup that makes you deaf. I listen to metal, rock and rap primarily. So answer this for me:

1) How many speakers should I buy, where should I place them (unless you suggest four, front or back of car) what brand and what specifications
2) What brand of sub woofer should I buy, where should I place it and what specifications
3) What brand head unit should I buy and what specifications? I probably sound dumb for asking this, but head unit replaces the stereo in the front console right?
4) What brand of amplifier should I buy, where should I place it and what specifications

Feel free to let me know if I'm not specific enough or forgot to say something in my question and I'll post additional details. Like I said, please do not go into a lecture talking about all the sound stuff. I just want to know your recommendations to the four questions I listed. Thanks.