If you choose "Account need validation" when you create your TTT account then all new users that register to your TTT account will need to be validated before they can access their own account and start update troops counts and all other stuff.
To validate new users you must go to "Users Validation" page from the left menu (See Img.1)
In this new page, if you have set more then one alliance you can choose from a drop down menu an alliance to validate user for and a list of users that are waiting for validation. Pick-up an users and click on "Validate" link next to his Username (see Img. 2)
At this point a new page is open where you can edit users information like username, ally, tribe etc.
To validate user account go to bottom of the page on "Account settings" tab and set "Account is activ" to "YES". If you have fake accounts that need to be deleted you will need to check "Delete this user" check-box. (see Img. 3)