To add to what ESWBitto said:
So a while ago I cloned and updated my 1.6ST (modified) and performed an update to 1.7RC2, and then updated it to 1.7RC4, 1.7RC5, and 1.7RC6. I was never able to get FAQs to work at all. More specifically adding and editing them.
I logged in with my admin account and enabled them at:
Admin panel -> Knowledgebase
Yet still Categories and Add New Faq never showed up.
So I went and inserted some generic information into my database into ost_faq, ost_faq_category, and ost_faq_topic (respectively) and a FAQ shows up... but I still couldn't edit it.
Apparently upgrading your installation does NOT assign the admin user (or its group) the privileges to manage FAQs. You have to go to:
Admin panel -> Staff -> Groups
Click on the group that you want to have privileges (mine was called Admin)
Enable "Can Manage FAQ" (near the bottom)
NOTE: "Can View Staff Stats" was also disabled in my admin group.
Once you have done that you should be able to follow ESWBitto's directions just fine.
I've added a quick how to here: (http://www.tmib.net/help-setting-and-using-faqs-osticket-17rc6) for anyone else that runs into this problem.