Basic knowledge about your Saturn is learned by doing. Checking the oil, for example, is covered in the car maker's literature in the glove box and easy to learn. But if you want to advance into repairing, servicing and maintaining your car, first buy a repair manual by Chilton or Haynes Publishing from The Motor Bookstore.
Cars from the 1990s to the present are much more mechanically complex than earlier models, but by referring to the repair manual, complex issues becomes managable projects.
You may also find that doing the work yourself is quicker than arranging a drop-off at the dealership, and then retrieving the car later. Each procedure is described step-by-step, starting with the tools you'll need, the supplies to gather, and shortcuts and tips to get the job done right.
Each book is divided into sections, and each section covers a particular component starting with Routine Maintenance and Servicing, then chapters on the Engine and Engine Overhaul, Emission Controls, Trouble Codes and Diagnostics, the Fuel System, the Chassis Electrical, Drive Train, Suspension and Steering, Brakes, Body and Wiring Diagrams.
Haynes and Chilton manuals are fully indexed for easy access to the page and section you need.