Getting error "404 Not Found" for subdomains

I've gotten some great help with setting up our multisite, downloading themes and getting a lot of ducks in a row. Now I started to try to build some blogs and can't access the dashboards.
I get this -

"404 Not Found
The server can not find the requested page: (port 80)
Please forward this error screen to's WebMaster."

What am I doing wrong now?