you have to invest alot of time and brains and very little money-- only for domains and hosting.. All other has to come later.. When you have 100sites you are allready succesful.. Only thing left is to become rich..
To be succesful you need to follow trends like now it's myspace, so make 100 myspace websites with st00pid content for st00pid people that spends all the day on myspace. Or have a st00pid idea like youtube and myspace!