I agree- remove the SIM and you won't get any data. However, I'd also disable mobile data. And, removing the SIM will probably pop up a warning that there's no SIM.
To stop network data, open Settings, More networks, Mobile networks. Remove the checkbox from "Mobile data" and you won't use any mobile data.
My Android devices:
vzw Samsung Galaxy S4 stock NC5 rooted
Samsung Galaxy Tab 2 10.1, also stock but rooted.
VZ Droid Incredible 2 rooted but otherwise stock.
Samsung Galaxy Tab 10.1