The number one rule in taking care of your car is to read the owner's manual. The instructions in that manual are specific to your car, and in most cases, the picture diagrams will be very helpful in guiding basic maintenance work on your car. Below, however, are four simple jobs you can do no matter what type of car you have:
1. Check the engine oil: The engine is the most essential and most expensive part of your car, and it can't run without oil. Check your engine oil level by removing the dipstick (which may have a ringed handle) and cleaning the oil off of it. Reinsert the dipstick completely, and then pull it out and check whether the oil on the dipstick rises to between the "Empty" and "Full" levels. If it doesn't, you'll need to adjust the oil level accordingly.
2. Check fluids: The fluids under your hood include brake fluid, transmission fluid, power steering fluid, engine coolant, and washer fluid. Each of these should be at least half-full, and if you have chronically low fluids, you may be suffering from a leak. Once you're fluids drop under half-full, refill them according to the instructions in your owner's manual.
3. Clean the battery: If your battery develops "snow" or any other substance on its contact points, you should wipe that off with a cloth.
4. Listen: Technically, you're not under your hood for this, but listen to your engine as you drive. Does it seem to be straining? Does it have trouble starting? Does it race at certain speeds? If you notice anything, mention it to your mechanic.