I have a starting problem and i dont know how to narrow it down or pinpoint it.

My car has various ways of NOT starting. Sometimes it'll turn over and just not start. sometimes it'll turn and start and just dwindle down and die. this happens mostly on hot days and it'll start at night when its cool. kind of strange.

recently it hasn't been too hot but the car will random not even turn and just click and not start. if i wait for a few minutes and try again it may do like what i had said before or actually start fine.

I don't know if i should look into connections with the ignition and the starter... or if its an alternator problem.

A friend of mine pointed out that since i have a 750 or so watt amp for my sound system in the back it could be hurting my alternator and suggested getting a capacitor.

Where should i start doing my research/say to a mechanic?

sorry for the lack of knowledge about cars... i really joined this forum for this reason exactly... problems and such.

THANKS

Pham