Speakers,amplifiers,subwoofer for my car?

-Hi.I'm hopefully going to get a car soon and I was just wondering what is the best sound system for a car?Im probably going to get a 2007 Dodge Charger and I would like to install it in my car,like in the trunk?Sorry,I'm new to this car sound system thing and also can a professional install it as opposed to me installing it(incorrectly)?Thank you so much.