Car has problems starting up?

Hi,

I recently had a problem with my car where it wouldn't start. Eventually the
battery just completly died. I brought a new one everything was fine for two
weeks, then the problem came back.

When I open the car door the light comes on I can turn the car power on and
everything on the dashboard comes on but when I push to start the car just
clicking. Whilst my car in running I'm reading about 14.2 volts, when ignition
is off it drops to 12ish volts (normal). I can then return to my car 19hours
later all lights come on again but the volts read 10.5 which isn't enough to
start, when I try to start the car the volts drop completly to 0.95. I can jump
start the car with leads/power block and the car works fine volt readings
normal. It couldn't be the battery as I brought and brand new one two weeks
back and it worked fine.

Just a little more info, there is a slight gap between the bonnet and bumper,
I'm thinking maybe damp HT Leads or an alternator problem. Any one have
any other ideas or had a similar problem. I'm not very car inclined so any
help is appreciated..