I’ve been following the 2007 Tour de France online using a couple different websites. The first is cyclingnews.com, which is a great news site for cycling. They have live coverage which updates frequently:
The other good website I’ve used is the official Tour de France page. If you follow the link below and click on the union jack (English) icon, it will take you to an info page in English. It has a lot of good information, including stage profiles and standings in the various competitions (General Classification, jerseys, etc).
I find the two complement each other quite nicely. The “newsflashes” for both are quite similar, but will often have different takes on the race. Also, letour.fr will talk with the “directeur sportif” of teams for their insight.