Especially because these are 'guy' sites,
please be extra careful to look at them first.
This is a real site that has an interactive car that you can learn what a car looks like under the sheet metal.
***
Great site with good pictures. Topics include:
How to check engine oil
Engine Coolant
Transmission Fluid
Tires
CV Joints
and more…
This is another site chucked full of information!