What I want to do is to have a shared calendar for the Training Department,
where people can go in and enroll themselves for classes.

I got one cool suggestion in the past: create a sign-in sheet in excel, and
save it in a shared folder, then do a "paste special" so that the sign-in
sheet shows in the white space of the appointment. Then, when people click
the visual link, they go to the sign-in sheet, and are able to put their name
on the list. When they save, it's supposed to update the link in the
appointment.

This has worked OK, but the biggest complaint I've received about this
system (from almost everyone in the company) is that this method doesn't put
the appointment on their personal calendars. (People here are Outlook
Calendar obsessed). Is there a way to do one of the following two things:

1. Keep the same system that I have going now, but somehow enable the
shared calendar appointment with the sign-in sheet copy to the attendee's
personal calendar.

2. Something different, still using the shared "Training Calendar," but
maybe not using the excel-linked spreadsheet.

Please help