Microsoft Online Services on microsoft.com:
http://www.microsoft.com/online

Microsoft Online Services Partner Portal:
www.quickstartonlineservices.com

www.discoveronlineservices.com

Technical FAQ for Partners:

https://www.discoveronlineservices.com/Documents/MOS%20Partner%20Tech%20FAQ.pdf

Microsoft Online Services TechCenter:
http://technet.microsoft.com/en-us/msonline/default.aspx

Documentation and Help:
http://technet.microsoft.com/en-us/library/cc498720.aspx

Online Forums on TechNet:
http://forums.microsoft.com/TechNet/default.aspx?ForumGroupID=566&SiteID=17

Microsoft Online Services Demo:
http://www.microsoft.com/online/demo/demo.aspx

Migration White Paper: 

http://www.microsoft.com/downloads/details.aspx?FamilyID=25350815-5c57-441a-b7fb-329ff5fe14b3&displaylang=en

Security Features White Paper:

http://www.microsoft.com/downloads/details.aspx?FamilyID=5736aaac-994c-4410-b7ce-bdea505a3413&DisplayLang=en

Microsoft Online Services Team Blog:

http://blogs.technet.com/MSOnline/

FROM THE MICROSOFT ONLINE SERVICES BLOG (https://www.discoveronlineservices.com/BrettsBPOSBlog/default.aspx): 

BPOS Training Buffett: an all you can buffet of BPOS technical and sales training:

https://training.partner.microsoft.com/plc/search_adv.aspx?ssid=E2FA8C2170C84D8B9BE34327B829594F

Lectures from the people making the services on the latest version of BPOS! New features for Exchange, the administration console and other parts of the service are all detailed by the PMs at Microsoft in charge of those features.

You want to know about how secure our data centers are? Check out Mike Ziocks highly rated presentation https://www.discoveronlineservices.com/Documents/Data_Center_Security_And_Reliability_110k.wmv

Interested in SharePoint Online capabilites? See it for yourself https://www.discoveronlineservices.com/Documents/SharePoint_Online_110k.wmv

How about Exchange Online and the new Conference Room features? https://www.discoveronlineservices.com/Documents/Exchange_Online_110k.wmv

Migration and Co-existence details and demo: https://www.discoveronlineservices.com/Documents/Migration_And_Coexistence_110k.wmv

Of course, there's using the Administration Center including how to add a custom domain to BPOS: https://www.discoveronlineservices.com/Documents/Microsoft_Online_Admin_Center_110k.wmv

David Wang presents a demo and details about the single sign on tool. Important details are included about how to deploy and configure. https://www.discoveronlineservices.com/Documents/Accessing_Microsoft_Online_Services_110k.wmv

Check out all the Virtual Airlift content on the Technical Tab!