I weould start by cleaning the terminals.
Also, how old is your battery, did you charge it and test it again per earlier post suggestions. If your battery is 5 years old or so, maybe it is time for a new one.
You may want to leave the terminals disconnected for this. Then check the the black (negative) to see if it is frayed with wire exposed, all the way to the ground (body of the car) and if the connections are loose. Then check the red (positive) all the way to the alternator. Again if the connections are loose or wire is frayed.
And before you do that, do a search on Troubleshooting and put "alternator wire", and all post. You should find a ton of useful information that might help you.
Good luck.
