A: Assuming that this is an on-premise installation, the minimal deployment would be SharePoint 2010 Foundation. It already resides on Windows 2008 servers and can be installed for no additional cost. The Content Database and all other services can reside on that one server. The caveat is future-proofing for size, traffic, and lack of features available on Standard and Enterprise Editions.

A SharePoint Foundation deployment would be perfect for smaller operations (both in number of users and overall size of content) or as a Proof of Concept. It allows you to introduce the platform and gives organizations the opportunity to begin with core SharePoint collaboration and out of the box approval workflows.

Be wary of the growth of multiple deployments of individual SharePoint Foundation installations within your organization. Linking them together eventually will require a great deal of custom configuring...