What Chop Smith said....
I started in this business several years ago, at first just to
see if I could make a little money (think HOBBY)...and barely
broke even with bandwidth, hosting, etc.
Since then, I've devoted a LOT of time and effort, and it has
paid off BIG TIME! The key to this business is TIME AND EFFORT - there will be times when you get discouraged, but you've just got to stick with it.
The best advice I can give is to learn how to advertise, build lots of sites, submit to link lists, make a traffic pump, etc., etc., etc., and stay away from legal stuff
Good Luck!