If you're reading this post, I'm presuming a couple of things.
You are interested in HealthVault, and you are in search of more information. Here's what we have for you:
HealthVault Developer Center
This is the MSDN developer center for HealthVault, and has all the information that you would expect to find it a dev center.
Well, actually, since this is a beta release, it's actually missing a lot of the information that you might expect. We'll be working on that in the coming months, but you'll need to bear with us for the time being.
HealthVault Blog (this blog)
This blog should keep you up to date on important information for the developer. If there's a new SDK available, if we add new data types to the system (more on data types later), or new content elsewhere - that's what you'll find here.
HealthVault Forum HealthVault FAQ Blog
These two work together to help you answer your questions. The FAQ blog already has a number of answers on it, and if you don't find your answer there, you can ask in the forum.