Red wire - positive of battery
Black wire - negative of battery and to the metal tube of the case. (assuming you have one - if not then you need to connect the black to both the negative of the battery and the outer of the connector you are using to screw your atomizers into - extra bit of wire will be needed).
Yellow wire - centre pin of the atomizer connector.
Remember this thing has the 5 click on/off feature, and will handle charging your battery in-situ (just screw the charger onto the atomizer connection as you would with a standard EGO type battery).