I'm not sure about document management, but the new version of Orchard (1.7, I believe slated for this week) is the first to have the Workflows module.
If you install 1.6.1 (latest stable,) it won't have it. However, if you enlist the 1.x branch, you can use the Workflows module. It's relatively stable from what I can tell, but it will be officially stable once version 1.7 is the new default.