I try to do minor maintenance on my cars but it is getting increasingly difficult due to all the electronics and extremely tight working area (ususally require special tools).
Some people shouldn't even try. My brother, who is not mechanically inclined, tried to change his oil once and forgot to put the oil drain nut back. He had 5 quarts of synthetic oil running down his driveway! The was the last time he tried to work on his car.