Okay, once you have installed your phpBB 2 forum and are logged in as an admin, go the the Admin Panel.
Scroll down the left menu until you find "Group Admin." Under this, find "Management." Click it. Then click "Create New Group."
Create a group called Moderators or Staff or Support Team Members or whatever you want to call them.
Now select this to be a closed group and select yourself as the group moderator.
Fill in a few words for the description of the group, e.g.
Group description wrote:These are the forum moderators.
Respect them and co-operate or face being banned.
Now save the group.
Go to Group Admin section of the left menu and under it, select "Permissions."
Select Moderators or whatever you called them from the drop down menu and click "Look Up Group."
You will now see a list of all the forums with a drop down menu next to them that is defaulted to Not Moderator.
Change this to Is Moderator for all forums that you want them to be able to moderate and click "Submit."
Now go to the index page of your forum and click on "Usergroups," and pick moderators (or whatever you called them) and click "View Information."
Look at the base of the tables and a text entry boxand a submit button called "Add Member." Put the name of a user you wish to make a moderator into this box and click "Add member." You now have a moderator group containing a moderator. Add all the people you wish to become make moderators to this group.
To make just a single user a moderator in only a single forum visit your admin panel and scroll down to User Admin in the left menu and then below that, click on "Permissions." Type the name of the user you wish to make a moderator into the text field and click the button.
From this page you may change a user to an admin also, but for moderators you will see a page similar to the Group Permissions one we discussed above.
Change the drop down column to next to the forum(s) you wish to make the user a moderator of to Is Moderator and select Submit.
You have now successfully created moderators for your phpBB forums.