A lot of the document doesn’t apply to what you want, but the AD and Group setup is very important.
To sum it up here is what you need to do:
Need to be on a Domain
Need to manually create required AD Accounts and Groups
Need to make sure remote access is enabled
Need to make sure the user you are using to install everything has the correct permissions on SQL and BizTalk box
Need to make sure you use the domain groups for the installation like DOMAIN\GROUP
These are the key things not to miss out on. The doc covers this, I think. You just have to sort out the items that do not work for you. I think some of this is also coved in the single computer install doc.
Hope this helps.