Quoted from CaptainNeo:
I did, and I don't understand who creates the coins and how they are giving them value.
A "coin" is no more than a digital "address", a 160-bit number that represents a value of bitcoins. If you lose that number you lose your bitcoins, period. The only known hacks so far are people stealing bitcoin addresses; in the case of Mt.Gox, from the inside.
There is a very good tutorial on BitCoin at Khan Academy, web search for "khan academy bitcoin". There are 5 parts but it's not that long.