Been creating a very long form in Drupal 7, as a custom module. Have had trouble understanding the db insert, but with some help have worked this out, and I do have a long, long form working on my local, and saving to the db. So that is good. Next important step has been breaking this long form up into a multi-page form, so it's not quite as unwieldy.
I followed the example module wizard code, and this was very good, but only got so far. Found sitepoint article on this which is much simplified, and based that article now have fully paged application form on my local, though does not yet do anything on submit. That's for another day.