I don’t know that there’s best common practice for this device…It really just depends on your business needs. I wrote some general firewall best practices that may help. Let us know if you have any specific questions.
For some general best practice documents always consider NIST publications. Check out the Special Publication 800-41 Guidelines on Firewalls and Firewall Policy and it’s proposed revision.
In the IT trenches? So am I – read my IT-Trenches blog.