The Newbies Manager in GlowHost's Spam-O-Matic Spam Firewall for vBulletin forums is built into Spam-O-Matic so that new users who register on your forum are automatically placed into a usergroup that has less permissions than your regular "Registered Users" group.
You will need to create this usergroup on your own, and then supply Spam-O-Matc with the numerical ID of this usergroup so that Spam-O-Matic knows what group to put new users into.
Once these users have proven their trustworthiness on your forums, Spam-O-Matic can automatically promote them to the "Registered Users" group or any other group of your choice based on simple post-count rules. If you want a more advanced promotion system, you can use the one built into vBulletin and disable the simple promotion system built into Spam-O-Matic.
You are free to disable automatic promotions from Spam-O-Matic and vBulletin completely, and then move the users manually if you like.
CAUTION: When you make your "Newbies" Group, make sure to do the following:
A) Go to your vBulletin Admincp > Forums and Moderators > Forum Permissions and make sure to give your Newbies a lower set of permissions that your Registered Users. (For example, turn off signatures and image uploads)
B) Go to vBulletin Admincp > > Usergroups > Usergoup Manager and permission the usegroup with a lower set of permissions than your Registered Users.
If you fail to perform the above steps it is possible that you have allowed your Newbies to view your private forums or other privileged areas.
It is strongly suggested that you permission your Newbies group before enabling Newbies Manager in Spam-O-Matic.