Brake Fluid Discussion
Dan's Online Motorcycle Repair Course    http://www.dansmc.com/MC_repaircourse.htm 
Eric Gorr Technical Articles    http://www.eric-gorr.com/techarticles/techarticles.html 
Gasoline FAQ 
Gasoline FAQ    http://www.faqs.org/faqs/autos/gasoline-faq/ 
How Stuff Works     A great place to come to learn about how things work in the world around you.   Animated engine operating principles.
Just XRs    Hondas, what else?    http://www.justxr.com/ 
Moto Professor Tech Index - http://www.motocross.com/motoprof/moto/mcycle/cycleind.htm
MX Tech    Suspension    http://www.mx-tech.com 
NGK Sparkplug Code     I found a couple of pages.
NGK Sparkplug Code
NGK sparkplug FAQ
NTN Bearings    General Bearing Knowledge
Oil article     The Great Oil Debate    by Rich Rohrich
Oil article    MC vs Automotive oil    http://www.nightrider.com/biketech/oiltest1.htm
Oil article    Motorcycle motor oil - Mike Guillory    http://www.yft.org/tex_vfr/tech/oil.htm 
Oil Filter Study - http://minimopar.simplenet.com/oilfilterstudy.html
Cylinder Porting     An Overview of Basic Principles and Processes By:  www.eric-gorr.com
Scott Osborn's Racing Gasoline     Get facts about gasoline and AVGAS!
Snell Memorial Foundation    We don't make helmets, we make them safer! Learn how helmets are certified
Spark plugs How to select and read them -   by Gordon Jennings
Sprocket Ratio Chart   Can't decide if you need a 14/48 sprocket setup or a 15/51? Have a look at this chart for answers.
Steve Fortner's Jetting Tips - http://www.ecmx.com/bike_tips/jetting.html
Table of oil properties