[support] Multiplicity

[Fred Jones]

I have a.com and b.com. Both will point to the same place. On home page 
we have two links: A and B.

A goes to a.com/a/ and B to a.com/b/. Thus all pages will be somewhere 
on a.com.

So each 'site' is really just a subsite of one site. The layout is 
virtually the same for each--only difference is the logo and the link to 
the other site (A links to B in the footer and vice versa). The menus 
and content for each site are entirely unique.

How should I set this up?

Either directions or a link for further reading would be appreciated.

Thanks,
Fred