I would recommend starting off with a reseller account from a reputable host. At least you won't have to worry about server admin/security and you can keep all your profits.
Alternatively, you could sell hosting accounts for existing hosts and earn comission.
Like many of the other comments on this thread, I would not jump into VPS and hosting. If you don't know how to run a server, then learning with live, paying customers is not going to be good for them, and you may end up destroying your reputation and may lose a lot of money.
Of course many of us learn from experience so it could fast track you into the world of hosting! But the cost may be high!
If you can, get a reseller and see if you can get enough customers to make it worth your while. If that works out, rent yourself a VPS and learn how to run it, then transfer over from reseller and try to grow. If that works out, then upgrade to dedi! If that works out, buy more dedis! If that works out, get a rack and start doing colo! If that works out, you may very well be a sucess and hey, its time to start your own data centre :-)