Your battery is STILL weak after such a short charge.
Your gasoline is old and decrepit (next time Stabil gas treatment's ad shows the guy with the fancy hot rod boat that won't crank, take it to heart), and if the car was parked with anything but a full tank, it probably has condensed several inches of water in the gas now.
Get some Sea Foam and see if it will help, and get that battery fully charged. Top up the fuel with the Sea Foam and premium gas.
Any numbers of sensors may have decided to glue themselves shut (IAC is a favorite in situations like this), and you might need to just warm up the whole car with a portable heater to get it running again.
Check the oil. If its worn out and low, change it, putting in a good grade of synthetic like Mobil 1 (the synthetics are less affected by cold conditions and storage).
If it still won't start, do NOT keep trying over and over until the starter overheats and ruins your day. Get out the workshop manual and start going through all the steps in the troubleshooting guide.
Check that you're getting spark at all the plugs, fuel to the motor, etc, etc.
Pull the OBD II trouble codes, you might have a stored code that will help explain things.
Originally Posted by johns46
I park my 2000 GT in an unheated storage building for the winter. It's about 40 degrees today and I haven't started it and let it run for about a month, so I went over to do that. The battery had gone dead. TOTALLY dead. I hooked up a charger and let it charge for about 30 minutes then tried to start it. It turns over just fine but won't fire. Never even tries. Checked the fuel pump reset in the trunk, no problem there. I don't know where to look next. Help!