Well if you're serious about making sure everything is right, first step would be go to lowes or home depot and get a thermometer hygrometer. I know at the Lowe's here, it was in the garden center, just outside. Once you know what the temp/humidity in there is, you can decide if it's fine, or if the next step is ventilation. Hell, you might even need to purchase a humidifier if your climate is really dry, cause when humidity is higher, it's easier to cool the given space.
Anyways, you could start all five with just a couple 23Watts, but in just a couple weeks you'll definitely wanna have at least 50 watts per plant, and in a couple more weeks you'll ideally want 100W per plant, or some people here use like 40W per sq. foot. Honestly for 5 plants, you should really consider HID lights, at least for flowering. You should take some pics, or give us the specs of the room so we can help better.