ArcGIS Workflow Manager stores its system tables in an Enterprise Database to allow for multiuser access. Options to install and configure an enterprise database are offered by Oracle and SQL, but an open source option that can get you up and running for free without much hassle is a Postgres database. This will allow you to deploy a db and start learning about Workflow Manager quickly.
Getting started with Postgres doesn't take much time and isn't complicated, but we thought we'd make some instructions to smooth out the process even further. Check them out!
From there watch our Getting Started with Workflow Manager video Video Link : 4040
or our recent online training seminar New Online Training Seminar - Simplify Data Management with ArcGIS Workflow Manager
Enjoy, and let us know if you have any questions
The ArcGIS Workflow Manager Team