car question. need help!?

[Zarus W]

ok, for the past couple weeks my car would crank up and start but it did it slower than normal. one morning i started the car and it still cranked slow. i put the battery on the charger for about an hour and tried to start it and it cranked even slower and didnt start. left it on there for another hour and it didnt crank at all. it sounds like it's trying to turn but it isn't getting the juice. uncle said that its the battery. i finally went today to check the battery and it checked out that the battery was bad. so i bought a new battery and put it in. turned the key and heard some clicking.....tried it again, no clicking. i thought from the get go that it could be the starter. is it??? never had any major problems with this car by the way... i have subs in the trunk so i just assumed that it was draining the battery. i didn't hook the sound up when i put the new battery in... so.....is it possible that when i put the battery on the charger, that just finished the starter, and continually trying to start the car just emptied the battery??? any help is cool....thanks