Hey Marie!
Are you a complete novice, or have you had any ballet training?
Are you in the city, or in the suburbs?
If you're in the city, and a novice, I know that Joel Hall in Andersonville has beginning level ballet classes; try Tonna's classes, she's very good. Also, in the Loop on (I think 128 North) Wabash, the Chicgo ballet school has beginning classes (I've never been there.)
If you have some experience, try Ruth Page (adult I classes by Rodney) or Hubbard Street (Monday ballet I or Wednesday ballet I-slow). Both of these have live pianists rather than music-on-tape. These, and Joel Hall, are the best places where an adult will get attention.
The suburbs are a different story. If you're interested in the suburbs, leave another posting, with an idea of the area.
The Joffrey does NOT have a school in Chicago.
Good luck! BalletMaster[/i]