If something happens to it I want to be able to diagnose myself. Maybe a good book or youtube videos?
Anyways, that being said, if your interest is fixing up your car, then yeah, as others have pointed out, shop manuals (3rd party or official) along with the web (google/youtube) is a very good starting point. I got interested in mechanics as a teen using these resources for small-engined vehicles (various dirt bikes and snowmobiles).
Still, I'll list some references I found interesting from the viewpoint of a young engineer designing a car from the ground up.
Braess, Hans-Hermann et Seiffert, Ulrich. Handbook of Automitive Engineering. Warrendale : SAE International, 2005. (Bosch is the most known "Automotive Handbook", but I liked this one better. Even though it's a 'handbook', it's still interesting to read, as opposed to Bosch which is really a reference. Good focus on passenger cars.)
Limpert, Rudolf. Brake Design And Safety. Warrendale, PA : SAE International, 1999. (Everything on brake systems and safety, with an interesting perspective from accident reconstitution. Good focus on passenger vehicles tool.)
William F. Milliken, Douglas L. Milliken, Race Car Vehicle Dynamics, SAE International, 1995 (known as RCVD, the 'bible' of vehicle dynamics, oriented mostly for race cars.)
Dixon, John C. Tires, Suspension, and Handling, Warrendale, PA : SAE International, 1996. (Similar to RCVD, somewhat shorter and easier to digest IIRC)
Ferguson, C. R. and Kirkpatrick, A. T. Internal Combustion Engines : Applied Thermosciences, Wiley, 2000 (Textbook I used in an undegrad course on ICEs, I liked it. The authors wrote some java applets that implement many basic ICE calculations, fun to play around with: http://www.wiley.com/college/mechs/ferguson356174/apps/apps....)
Wong, J.Y. Theory of Ground Vehicles. Hoboken, NJ : Wiley, 2008 (Mostly focused on various off-road vehicles, suspension, traction and handling)
Aird, Forbes, Race Car Chassis: Design and Construction, Motorbooks International (July 1997). (Good overview of 'classic' design and construction techniques for race car chassis. Somewhat dated in the sense that it doesn't cover modern composite chassis. Worked well enough as an intro for the design of our tubular space frame)
[1] The project website went offline, sadly. Here's some local media coverage (in french) http://www.lapresse.ca/la-tribune/economie-et-innovation/201...
Some cars are popular enough to have dedicated websites devoted to them with guides and forums (e.g. Smart car: http://fq101.co.uk).
It should be noted that servicing ones own car comes with pitfalls. You must invest in quite a lot of expensive tools, have a workshop area or driveway to do the servicing and ultimately if you fail to complete the task, you might end up with an unusable or dangerous car.
A good reason to know about how cars work and what goes wrong with them is that when choosing a good garage to have service it, you are in a stronger position and cannot so easily be tricked into having servicing done when it is not necessary.
One of the nice things about these workshop manuals is they rate jobs by difficulty and tools required, so you can start on easy stuff like oil and filter change and work up to the more advanced things like head gasket replacement.
I also learned a lot from my Dad, so if you know anyone who's knowledgeable in the field, see if they'll help you, or at least impart some knowledge.
Also, invest in a decent trolly jack and axle stands, I hate the thought of people working under cars supported only by the flimsy scissor jack that came with the car.