Amiga Future - The Big Book of Amiga Hardware (Hardware Information on thousands of Amiga Peripherals) - http://hardware.amigafuture.de/
Amiga Hardware Database (Similar to the BBoAH above but with driver download attached to the hardware itself, nice search function) - http://amiga.resource.cx/exp/
Amiga Power Supply Guide (Version 1.04 10th April 2006 by Ian Stedman - This document details how to diagnose power supply problems on the Amiga series of computers. It also details how to use a PC PSU as a higher power replacement for the Amiga and the necessary steps to make your own connecting cable.) - http://www.ianstedman.co.uk/Amiga/amiga_hacks/Amiga_Power_supplies/amiga_power_supplies.html