2004 Pontiac Grand Prix Battery draining while car is off Please help someone!!!!!

[postal G]

For some reason my battery is draining while the car is off and causing the car not to start first thing in the morning or after an 8 or 9 hour a day of work. I have to get a boost to get the car to start. When the car starts i notice that the air condition light is on and the clock has been reset. Also my radio will come on even though it was off prior to me cutting the car off.
I have a 2004 Grand prix gt Also when i do attempt to start the car without a boost i get a loud fast clicking sound.
I bought a brand new battery yesterday from sears and also had the alternator checked. Everything tested good.
Will someone please give me some advice on what the problem is. I'm trying to avoid paying so much to get this problem fixed. I've been researching this issue the last couple of days and i have read things to do like use an ammeter to find problem.,

[spazzz]

Sounds like one of the connections didn't get secured tight after the swap. Check for corrosion on any connection,clean and refasten. Trace your positive and negative lines,starting from battery and make sure they are secure. If they look excessively rusty,you should clean them and refasten. Other than that you might have a bare wire in the lines.

[postal G]

the connections are tight.

[spazzz]

You want to make sure you can't move the terminals on the battery what so ever, I mean tug on them good. They cant move a peep.