Use List Settings to control the content in a Team Discussion list and to require approval for postings. Choose Versioning Settings from the General Settings group. Click the first radio button to require content approval for submitted items. Check the bottom of the screen for a list of the users you intend to allow access to draft items.
It’s always a good idea to assign at least two approvers for a discussion list. When users cannot experience their involvement in a discussion, participation will wane.