Not sure where we would suggest this, but time and time again we see users struggle with creating or uploading a child theme.
It would be good if WordPress Extend had a sample basic child theme from the WordPress team, in the themes repository for twenty eleven and twenty ten?
We could then point users to the download page, a lot of themes have a child theme download option now!
David ("Just a thought!")
[moved to: 'Requests and Feedback']