Perhaps take a more Object Oriented approach;
create an object that is populated by the 1st form ("user inputs info"),
create a function within the object that "uses the users info" and call this method from the 2nd form,
create another function within the object "that displays a final result" and call this method from the 3rd form.
Check out
http://www.codeproject.com/csharp/ for more help.