abranger, it's pretty straightforward. For the greens, we blanch them until they're bright green or sautee them quickly in a hot, dry pan in the water that clings to their leaves from washing--this works for kale, chard, spinach and escarole, for sure. I suspect it would work for other greens, but we haven't tried it.
Carrots, broccoli and beans can be cooked in boiling water for about three minutes, tops, then frozen. You don't want to cook them as long as you would if you were going to eat them straight-away, because they'll be mushy.
For corn on the cob, you can shuck the ears and freeze them whole, or cut the kernels off and freeze them just like that. Corn doesn't need to be cooked at all before freezing it.
Carrots, beets, onions and squashes can be roasted, then frozen. I'm not sure what turtle plans to do with the beets (I've never kept them this way before), but the other roasted vegis are great additions to soups.