I just finished reading Superman Earth-One by JMS, and I have to say, I really enjoyed it. I know a lot of people have been down on him lately for his run on the main Superman book, and they would be down on his work on Wonder Woman if anyone cared about that character in the slightest, but this shouldn't be ignored because of those. I've always found that JMS works best in some kind of vacuum (Babylon 5, Rising Stars, etc), and that's sort of what this is. Superman's beginnings as if this is the first time it's happened, and it's happening right now.
It's mostly not even about Superman, but about a young Clark Kent who would rather find a job where he can use his unique talents to make enough money to be happy, and to take care of his Ma back in Smallville, and never have to pretend to be someone else, or let the world know he even exists as anything other than a successful man, until he is inevitably forced to take on the role of Superman. It's a great read, and I recommend it to any comic fan.