There's another great screencast on Exchange Online Services over at the BPOS Tutor site.  Click the image below to watch the BPOS screencast.

There are a couple of good posts out there with screencasts on configuring your BPOS account.  Check out these two BPOS tutorial posts by clicking the links below.

1.  http://www.bpostutor.com/post/Configuring-Spam-Junkmail-and-Safe-Senders-List-Setting-for-Microsoft-Online-Services-and-BPOS.aspx

2. http://www.bpostutor.com/post/Create-new-administrator-for-your-BPOS-account-with-Microsoft-Online-Services.aspx

There are two great screencasts over at BPOS Tutor on signing up for BPOS and configuring your domain to work with BPOS.  Check them out if you need help signing up for a BPOS trial and then configuring your domain which is the first step after you are able to log into the administration center for BPOS at https://admin.microsoftonline.com.

Screencast on signing up for a BPOS account

Screencast on adding, verifying and enabling inbound messaing on a new domain for your BPOS account