No start, no interior lights, nothing

I have an 01 jetta and the other day when i went to start it, the dash lights would flicker and a black box would click and then it got to the point where that black box with 2 connectors (im guessing is some kind of bcm) would click even with the ignition off. I unplugged it and now nothing happens at all anymore. If anyone has had any problems like that it would be greatly appreciated if someone could help on where to start looking for problems
Thanks,
Nick

There's a big thread (sticky) about no start conditions around here.
But if you've never checked/cleaned the electrical grounds under your battery tray, that's a good place to start. All the grounds in a car that old should be inspected/cleaned or re-seated if needed by now...
BTW what's the black box you're referencing?

Start by checking your battery's voltage.

Yeh battery voltage then battery cables and so on, make sure the connections are all tight at the gear box and starter as well as the battery terminals.