Hi Lisa,
we are multiple authors in different location and used VSS
until about half a year ago. We spent a lot of time on checking
files out and in again, but we didn't integrate it with RH, maybe
that makes working with it easier. We switched to Subversion, which
allows multiple authors to access the same files at the same time,
and changes can be merged later (no need to lock files). For us,
this is a big advantage. Also, its freeware! However, our company
had already used it, and we have some experts here that know how to
set it up etc. We never had the problems with the Robohelp output
folder that Benjaminson mentioned, because we excluded it from
source control.
Good luck,
Kathrin