Electronic Controls Document:
Details of the internal wiring, pin-outs, and other electronic details.
Hydraulic Schematic:
(Left is the key document, right is the actual schematic file) Details of the internal hydraulic routing and their functions.

Transmission Overhaul Detail:
Factory detail of a complete transmission overhaul.
Conversion to Manual Shift:
An interesting article detailing how to convert an eletronically controlled 4L60e into a manually-shifted transmission.