GeneralHavok on "Add input to Comment form"

Need a hand. I'm not a noob, but I'm puzzled by the instructions/tutorials I've found for customizing a WP comment form.

Quite simply, I want to add an input to the comment form. Seems like the following is needed:

1. Add the input (and label) to the form.
2. Store the data in the database, requiring a new field.
3. Retrieve the data for display on posts.
4. Add the data to the Admin for viewing/editing.

Could somebody lay out, in simple terms, how this is done? Again: I've read EVERYTHING I can find on this, but the info is either outdated or I don't understand it.

Thanks for your help!