Auto Shop 101
Under the [Technical Articles] section, numerous PDF files can be downloaded with great automotive mechanic content.
Fluke 98 User's Manual
Even if you don't own a fluke, the sections describing tests and how to interprete results are very informative.
Car Complaints
Able to view people's complaints for Year/Make/Model. You can also access Recalls and TSBs.
Engineering Explained
A Mechanical Engineer with a passion for cars. My favorite video is the one discussing the difference between Horsepower and Torque.
Eric the Car Guy
A Professional Mechanic that shares his experience, his daily jobs, and tips and tricks.
EE Video Blog
An off-the-cuff Video Blog about Electronics Engineering, for engineers, hobbyists, enthusiasts, hackers and Makers
Mitchell1 DIY
A leading source of factory diagnostic and repair information for over 30,000 vehicles between 1983 to current.
James Danner
Scanner Danner's brother. He is another awesome, ethical mechanic which creates videos to share his knowledge and know-how.
Circuit Simulator
I utilize Paul Falstad's Circuit Simulator to play around with circuit designs to understand how they work.
Schrodinger's Box
A Chemical Engineer that is an advanced DIY automechanic. He really pushes the concept of not being a parts changer.
ALLDATAdiy
A leading source of factory diagnostic and repair information used by 200,000+ technicians.
General TroubleShooting
A general list of troubleshooting procedures to help the DIY mechanic get going on an issue
Mig Welding
One of the many great welders on YouTube. He taught me that MIG welding is something you feel and listen to.
Summit Racing
When placing an order, they will most likely have an expert available to help you purchase the proper parts.
ADPTraining
Auto Diagnostics and Publishing web site. They publish good YouTube training videos, teach you how to build your own test equipment, and sell unique automotive diagnostic tools.