Question [Q] A501... where to begin?

I've attempted to follow a dozen different "Noob/beginner" and "all-you-need-to-know" sort of guides here and still feel stumped. My first tablet and by far the most difficult to actually tinker with - to date for me.
I have an ATT Acer A501 Tablet.
From what I understand; Android Version: 3.2 = HC, correct?
However; Build Number: Acer_A501_4.402.03_PA_ATT
From the "unofficial official OTA updates" thread somewhere in here, It doesn't even get CLOSE to a "4.402.03". I believe the highest was "4.1XX.XX", which from my basic understanding means.. I have no idea.

Wouldn't the higher build number represent a newer OTA/Newer build? If that were so, Why is my version at 3.2?

I don't need an elaborate speech on how I don't search. I don't need a flame fight or a "google it" response.
I need to know where to start with getting this thing fully unlocked.