<p>How would I upload a file to a webserver using c++ and MFC.  We are not using .Net.  Would I need to open a socket and do everything myself?  If so, where is a good reference to follow?</p>

You don't want to use direct socket calls. It's hard to get HTTP right this way.
The easier way is to the WinINet APIs. Check out the docs for InternetOpen, this will likely be the first call you make. Functions you will likely need:
InternetOpen
InternetConnect
HttpOpenRequest
HttpSendRequest
HttpQueryInfo
InternetCloseHandle
You can find docs for all of these on msdn