I dont do any cardio while bulking, i am a pretty active person, so i dont feel a need for it. but when im cutting i usually do 20-30 minutes post workout 4-5 times a week. Im one of those lucky fellas that can lose fat fairly fast if i need to.
Before I work out, I do a small session of about 5 minutes to just get my blood and oxygen flowing through my body. I never over due it though to the mile range or anything. Aside from the fact that I shouldn't run because I'm bulking now, I should run a little longer on my days off because I have palpitations once and a while with my heart. (The running part would help me increase the strength of my beats)