its all about what your normally used to and how fast you want to gain.
if you normally do cardio all the time, don't stop when bulking. if you normally don't do cardio, bulking is not the time to start doing it...cutting is. your body has a point of homeostasis that its used to and a set metabolic rate it has conditioned itself for over time. you don't want to give your body a mixed message. if you normally do cardio all the time, and stop while bulking, do not increase your calories or be prepared to pack on some fat.
also, if you're naturally lean you can afford to eat more than 500 extra calories when bulking...maybe an extra 1000-1500. but if its naturally hard for you to cut up, then an extra 500 when trying to bulk should be all you need because you have a slower and less efficient metabolism in the first place.
its important to know that things you do affect your body in each direction from its point of homeostasis. lets call 0 (zero) your point of homeostasis and use positives (+) to illustrate an increased metabolism (fat loss) and negatives (-) to illustrate a decreased metabolism (fat storage).
1) steroids are +1
2) off cycle is -1
3) cardio is +1
4) no cardio is -1
5) extra 500 calories is -1
6) extra 1,000 calories is -2
7) growth hormone is +1
8) insulin is -1
9) thermogenics (ECA, T3, DNP) is +1
add up the cumulative of all these numbers (theres probably more, these are just the main ones) and you'll see which direction your body composition will shift from homeostasis and how fast it will shift.