Any website for basic automobile parts know-how?

i own a hatchback car of age 4. Till now, no big cash-drain on my car for parts except for tinkering of condensor of AC..But of late, i find my driver citing one reason or other for cash for minor repairs eventhough my car runs perfectly good and noise-free.I thought, its time to know something about car parts and machinery. Can people suggest any websites for dummies like me who know nothing about car to start with....