I copied the following files to C:\Program Files\Autodesk\3ds Max 2011:
cudart_64_42_9.dll
FreeImage.dll
FreeImagePlus.dll
octane.dat
octane.dll
I then deleted cudart_64_40_17.dll from the \3ds Max 2011\ folder (if I don't do this Max crashes on start-up. After I delete it Max loads but not Octane — this makes me think the plugin may be looking for the wrong cudart file name when it loads.)
I also copied the file Octane3dsMax.dlr to the ...\3ds Max 2011\Plugins\ folder