Personally i tend to only do cardio if i'm having an off day and find it hard to get motivated, but normally straight onto weights after. Probably the wrong way to see it but i see it as wasted cals as i want to try and bulk up and find it hard enough as it is to get enough of calories throughout the day, still try to get a good balance though.

Although I've heard that a 20 minute cardio session in the morning can be a good way to boost your appetite through out the day when bulking too.

Guess it depends on your goals too i suppose.