All the sudden my car wont start.. I just put a new battery and a new alternator in it.. When i turn the key, it stresses slowly and tries to start for a few seconds then goes rite to a clicking noise. And it only starts up when i jump it... Starter,,?? Grounds?? any one have any idea what it could be

 

sounds like a weak battery, could also be the starter solenoid. jump the solenoid to itself with a screwdriver or something, if it turns over fine you may have found the culprit.