You can use fresh broccoli, frozen, or what I like to do is get the pre-cut, pre-washed package of "fresh" florets. Just divide it all up into a few snack-sized portions in a zip-lock bag, add a teaspoon of water and toss in the fridge (no water needed if it's frozen).
When it's time for a snack, toss one of the bags (with the zip NOT sealed!) into the microwave for about 30 seconds (depending on the power of your microwave). This will steam the broccoli in the bag.
Remove and add a tablespoon or 2 of your favorite dressing (I like low-fat Ranch), seal the bag and shake it up to coat everything with the dressing.