[Radiant] Need help understanding how to use the multi-site extension

[Wes Gamble]

All,

I've installed the multi-site entension, but am not sure how to use it.
Here are some questions:

1) Is the "domain match" field for a subdomain of the "base domain".  So 
I'm guessing for example, if base domain is "company.com" and "domain 
match" is "sprockets", then "sprockets.company.com" defines a separate 
site.  Is that right?

2) Is the homepage ID the actual DB id of a page object?  Or is it a 
slug or what?

Thanks,
Wes