How do I... Power Relay for Lights?

Put fingers in ;-)

arduinois great for starting with all this. the website is a good starting point and of course an arduino starter kit (board and basic electronic parts like resistors, LEDs, …).

i can also recommend this book for getting started with electronics and this and this and this for arduino projects (books are in increasing complexity order).

and yeah, lot’s of patience :)

Gilbi: just tell us wich type of lighting source you want to use for your project ( Leds, hallogens, power if hallogen, voltage ( 1,5v-12v-220v + watts of the lamps)) and this will be more easy to help you quickly on the hardware part: with the electrical specs of your hardware for lighting it will be easy to figure out a plan for you, with all parts and cabling way.

Arduino fundamentaly allows anybody to interface simply electronics with the PC, and protecting it from mistakes in cabling.
soldering is not obligated, you can choose to screw if you are not confident. There is breaboards tat are nice on first steps.
Time you will put in arduino is like time you put in VVVV: a great benefit at the end.

what motzi said! :D

You could also use this relay board in connection with an phidget interface kit. Just have a look at page 5 of the manual and IO (Devices Phidget InterfaceKit 888) . Easy as can be.

and arduino…