Your new V3i kit is exceptionally easy to get set up!
If you are using the filled cartomizers, simply remove one from the blister pack and screw onto the top of the battery. Make sure that the rubber bung is in place at the other end of the cartomizer (the end you'll inhale from), and you're good to go!
If you are using blank cartomizers, you will need to fill these before screwing on the battery. Simply remove the plastic bung and then drip e-liquid from the bottle onto the wicking material inside the cart. Let the liquid soak in before dripping more, and stop when the material is fully saturated.