It might seem like the security policy is something to be drafted, reviewed, and approved once, only to be filed away and almost forgotten. IT security policy management is more than just document creation, and much more than just a check-box on a to-do list. A well-conceived and well-managed security policy can provide a clear vision of the organization's security goals. You might begin with an example IT security policy if you don't know where to start, but you shouldn't depend on a template to meet your requirements in full. Remember that your security policy may be audited later.
Even better, a sound policy delineates a path to follow for processes and procedures to make that policy an operational reality. If you have defined what groups have what users, what their roles are, and what resources those roles allow them access to, and what kind of access, at what times, it's straightforward to go from there to modifying access control lists (ACLs), firewall rules, directory group membership, content filtering, and so on.
Simply enacting a policy and letting the operations staff, administrators, and technicians run with it isn't enough. Security policy management is an ongoing process. It's predictive and assertive in my opinion, not merely reactive. Choosing technology that makes it easy to implement policy can make or break the success of that policy. You may discover after creation of a strong, business-focused security policy that the technology you have in place isn't capable of supporting it. (Time to upgrade...)