Need help with car speakers!!?

I recently bought 4 x 45watt car cd/dvd player and a 9400watt amplifiers ( i have no idea about the watts). now i went to this guy to get it attached to my car speakers but he told me that the spears that i currently have will be destroyed if i connect it. So i need to get speakers and a woofer.. Now the problem is i don't know where to start. How many watts speakers do i need and woofers?? i read in some forums abut watts and amps and RMS, etc etc but i don't understand anything for S**t!!! Help me!!