Here's a video tutorial on creating PDF Forms:
http://video.brainstorminc.com/Video-Content/Online-Players/Corel/Corel-X6-QuickHelp-for-Corel#pvid=484
For "fill in a pile", normally each person who receives the form fills it out once.
For exporting the data, the users can either send back completed PDF forms, or you can add a submit button that allows them to send in a smaller file with just the answers. This file is readable in Acrobat Reader.
A "Select One" can be a drop down list or a radio button.
A "Check all that apply" is a series of check boxes.
Fillable forms are under Insert, PDF Form Controls.
Regards,
Douglas
Corel Support