I've got some more links to post.
Recently there was a piece on NPR about Superman.
Then there are parts 6 and 7 of the Fortress of Soliloquy's analysis of Superman's origins. While we're at it, the same blog has some interesting thoughts about Superman 701, the first full issue of the Grounded story where Superman walks across America.
On the same subject, here is a page of links to reviews of Superman 701, courtesy of Comic book resources.
And here's another review. From Living Between Wednesdays.
Moving along, here's a list of the 10 Superman comics you must read.