Minecraft wiki entry for Redstone, associated text: Redstone dust: The core material that enables most redstone devices, being crafted into many of them and also placed to carry signals.
Mechanics/Redstone: The basic game mechanics for redstone power and signals.
Mechanics/Redstone/Components: The blocks that are used in and with redstone contraptions.
Tutorials/Redstone tips: Hints and advice for building your redstone devices.
Mechanics/Redstone/Circuit: Lists various types of reusable circuits that can be used to manipulate signals, with sub-pages giving examples of the various types.
Help:Schematic: The "modern" way for redstone circuits to be represented on this wiki.
MCRedstoneSim schematics: An older method for displaying redstone circuits.