One of the most important factors in setting up an indoor grow is the lighting structure, at the end of the day your yield is going to depend on how efficiently you used your light, this will maximize each plant to its full potential.
First I will start off with what NOT to use, incandescent and halogen light bulbs should not be used, even incandescent light bulbs marketed as grow lights, avoid them all.
Next up is fluorescent lights, these can be used in the very early stages, but again avoid them if you can, and they are not acceptable for older plants in the flowering stage.
Now the lights you DO NEED are High Intensity Discharge(HIDs). There are two types of HIDs 1) Metal Halide 2) High Pressure Sodium. These bulbs come in varying wattages so here is how you decide what you need by square feet.
less than or equal to 10 square feet ~ 250 watt bulb
less than 20 but greater than 10 square feet ~ 400 watt bulb
less than 50 but greater than 20 square feed ~ 600 watt bulb
50 or greater square feet ~ 1000 watt bulb
The difference between Metal Halide and High Pressure sodium is the type and amount of light emitted, your Metal Halides will produce a more sun like yellow light while your High Pressure Sodium will produce a more orange type light with more lumens per watt; thus your High Pressure Sodiums will produce more light per bulb than a Metal Halide. The choice is really up to you what to use; some people use both at the same time; some people use Metal Halide during early vegetation and switch to High Pressure Sodium once plants are moved over to the flowering stage.
Remember to always use hood with your lights so light emitted is directed strait at your plant.
Now you CAN'T just plug these lights in to your normal sockets at home, in order for these lights to run, you will need to get a Ballast.
Hook this up and make sure ONLY the lights are running on this circuit, otherwise circuit fuses can certainly blow.
Once the lights are set up you must position them as strategically as possible above your plants, a good rule of thumb is to put anything less than 1000 watts about 12 inches above your plant and 1000 watts at about 24 to 30 inches above. If the light is not close enough to the plant, you will produce less buds.
When hanging lights don't forget to use an adjustable chord, as the plant grows, you will need to raise your light and hood. If an adjustable chord is not an option use risers for instance a wooden box or a stack of boards, continue to lower the riser as the plant grows.
The surrounding area of your grow should be set up so light is reflected back onto the plants, paint the walls white or use a reflective plastic so that the energy is not absorbed into the wall.
"May The Buds Be With You"