As I already said, I'm a rookie, I can program in different lenguage but I'm not very an expert with electronics, so I'm wondering how can I switch on/off my led strip, I got two options at this stage, plugging 12v directly to the power plug of my Arduino or use the Vin as a power source, furthermore how will I manage to switch my LED strip on and off without using any kind of relay? hum... hope someone out there could point me..

EDIT:

Peter Walsh gave me a very beautiful and exaustive answer here!