Disabling the NES Lockout Chip by Mark Knibbs
Gold (Zelda) NES modification guide in both txt and html (beware, 575k of pictures) by AndrewM.
Info on how to replace the NES 72 pin connector by XBJ-9000
Info on how to make an adapter to plug an NES Controller into, by Tennessee Carmel-Veilleux
Mario NES Mod by Dustin of Video Game Rescue
Mega Man NES Mod by Dustin of Video Game Rescue
NES Cleaning Guide Version 1.0 by AndrewM
NES Cleaning Guide Version 1.02 by AndrewM
NES Controller Lengthening FAQ/HOWTO v100 by AndrewM
NES Controller Lengthening FAQ/HOWTO v1.00 (Spanish) by AndrewM, translated by Switchstance
SNES to NES Controller conversion Guide by Mark Knibbs
switchNES modification guide (how to put a power switch on your NES) in html by AndrewM
Zelda NES Mod by Dustin of Video Game Rescue