Thanks for the reply, Stephanie.
I guess I'm a little confused. When you "publish" a form, it's always published to a forms library. Since that library could be made to behave the same as any other list, I can't see when you would use a list and not a forms library?
Anyway, since this is only my third form I had a lapse of memory and forgot about the "publish" step. I went about first creating all the fields in the form. Then when I got to the Submit step and set it up to publish to a forms library, the data elements are bound to "Main" and the Sharepoint forms library is not a selectable data source.
Also, just a quick clarification on an observation. Do Rules always get executed first by default over code?
Thanks!