>I know drone cells are larger than "other" cells. Someone posted today that food cells are also larger...possibly for conservation of materials. All those "other" smaller cells would be for brood, then.
If bees build their own cell sizes, in other words not mislead by foundation, yes.
>I see in catalogs that I can get foundation with different sized cells imprinted in the wax (or plastic).
That's because over time they enlarged the standard worker cell in foundation (which in the mid 1800s in Italy was 4.6mm and in the rest of Europe and the US was between 4.9mm and 5.1mm) until it was 5.4mm. Some people are going back to the smaller.
>Question: When I order everything for my first hives this winter, I need to get two different sized cells: smaller cells for hive bodies, and larger cells for supers?
No. Typically people run brood comb everywhere unless they are doing drone trapping or they are trying to raise queens for queen rearing. There are a few proponents of using drone comb in the supers (with an excluder) because they are easier to extract but that is not the norm.
Most of the cell size issues are whether or not you want large cell (the status quo in the beekeeping industry) or small cell (a regression back to the size of foundation at the turn of the 20th century).http://www.bushfarms.com/beesnaturalcell.htmhttp://www.bushfarms.com/beesfoursimplesteps.htm
#2: What happens in the hive body early in the spring (before supers are added) and they need drones? They have to either raise drone brood in smaller cells, or build cells that are not perfectly constructed on the smaller imprinted wax, right?