A: Microsoft provides load stress test tools to emulate logon sessions and workloads within the sessions that can be scripted to perform many actions. The downloads include the stress test tools in both 32-bit and 64-bit versions, plus documentation on using the tools and a reference guide. You stress test environment will consist of a test controller host and a number of client workstations that initiate the automated connections and load, in addition to the target Remote Desktop Servers. This is all documented in the downloaded documentation.
You don't need one client machine for each connection—Microsoft has tested 50 client connections from each client—but the number that works for your environment will depend on the client hardware you have available and the tests you're performing.