Do I need Cardio ??

I am about to start my cycle and was not sure if doing Cardio is really a good idea if I am tiring to bulk. The only reason I am asking this question is that I want to get rid of my gut and work on a six pack. If I should do cardio what should I do and for how long?

Thanks

you can either bulk, or you can cut(get the 6-pack), but you cant do both at the same time. i do no cardio while bulking.

Sit-ups still ok, right?