There are services like Valueclick.com that pay you to show their ads on your site on a CPM (cost per thousand) or CPC (cost per click) basis. They don't pay a lot of money but at least it can give you some extra income until you figure out what to sell on your site. You can also join a few affiliate programs that sell products your type of visitors may be interested in, CJ.com, BeFree.com, Referit.com are some good places to find affiliate programs.
Good luck!
Alex Fuentes
http://www.PrimeProfits.com