sorry, but this forum is primarily for installing computers in cars. so audio advice is a little slim..
anyways,the first major thing you will run into is that you need to search--no one wants to help someone who is not willing to help themselves.
for a start, a site like crutchfield.com has a lot of resources that can help someone just getting into car audio.
also, i will not give brand or speaker recommendations--every car, and ear is different, and what you like might not be what i like when it comes to equipment-- build the system you want, not the one others want..
the perfect car audio system is the one that sounds best to you-- to some, this might be a $5 boom-box, to others, it is $50,000 in audio equipment-- and neither opinion is wrong..
a great example of this-- i don't like infinity, or sony car audio, but many do-- so even if you liked them, i would steer you away from their products, even though there is nothing physically wrong with their products...