Microsoft has been quietly updating their Windows Phone site to include Windows Phone 7. The links to see the phone line-ups is a dead-end, taking you to a page that simply reads, "No Devices Found". But the Help and How-to link has a lot of information on the upcoming phones.
Everything from the basics to email to Office Mobile is covered. You have information on how to set up your Windows Live ID and your XBox Live Account. There is so much information in the Help and How-to site that it's a little overwhelming.
The site is basically an online owners manual for Windows Phone 7 and is a good way to get familiar with OS before it hits the shelves.