You'd have to order them by date in some form, I do this by a field called position, which is yymmddhhmmss, and then ORDER BY position DESC gives me the newest entries at the top, by simply updating this field when images are updated you'd get the list.
To just limit it to 10 or whatever, use LIMIT 0, 10 to display the first 10, I'm not sure on the exact specifics of this, (except that it goes into the SELECT statement of course) as I've personally never used it.
www.mysql.com should have more userful information on LIMIT.