Welcome aboard.
I've never used a car cover on my own vehicles but I know people that have and for the most part I know a lot of people recommend the "Stormforce" covers. Supposed to be really good quality all weather breathable covers.
Most important thing though before putting any car cover on is to ensure your car is properly clean as any dirt/grit/dust etc will damage/mark the paintwork when the cover is fitted or moves around with the wind.
Some pictures here in this old for sale thread: http://www.350z-uk.com/topic/87728-350z-370z-stormforce-fitted-car-cover/
Current new price here for example: http://www.coveryourcar.co.uk/store/product.php?productid=17421