haha i read somewhere a guy was gonna go around australia so he bought an old landcruiser or landrover or something, took every single bolt apart and the whole engine apart (maybe) in his back yard, put it all back together again and drove around aust! would have known how everything fitted together pretty darn well! so i think thats quite a good principle to work off.. not necessarily taking apart the whole car haha but if ur working on a certain bit fiddle around with it and see how u go.
i learnt from my dad a fair bit, most of my friends whos dads/relatives arent into cars find it a fair bit harder to get the head knowledge of cars and be motivated to work on them a lot, still i think cars are absoltuely 'learnable'! get one of those car manuals, search and read LOTS of forums, but like ke70dave said there can be some dodgy stuff on them, generally i think its usually pretty good, but its prob good to double check the info with ur manual as a bible as such lol..