First I'll describe the traditional recipe, one that's got lots of fat in it, and then I'll show you one that's more health conscious. 

In a large pot, the bigger the better, put in a little olive oil and add an entire onion (large) well diced.  Add a half dozen strips of bacon and cook that until it's done enough to have provided quite a bit of fat.  Then add a couple of ham hocks and enough water to cover them well.  Let that cook for about ten minutes, maybe fifteen, and then add the collard greens.  Fill the pot to the top, but don't stuff them down into the pot - just fill it up.  Put a lid on the pot and cook it for at least two hours.  Depending on the size of your pot, you might want to cook then three to four hours.

You'll have to check the greens occasionally to make sure they've got enough water.  Don't add a lot of water because the object is the steam the greens rather than boil them . . . at least for the first half hour.  After that, the greens will have cooked down to less than half their original size.  Add just enoug water to make sure the ham hocks are cooking and the greens aren't burning.  Make sure you cook over low heat. 

Now, if you want to cut back on the fat in your greens, leave off the bacon and other oils you used to start the process.  You'll still want to start with a little olive oil and onions, then dump in the greens and add a little water.  They'll still taste fine, but I still add the ham hocks.  Some people add chicken stock, and that's fine, just adds more fat and calories.  And I play around with the recipe and add some sugar (not a lot, but some), and even quite a bit of black pepper.  Some folks also add garlic, but I don't.  The onions work fine for me.

As for the cornbread, you can come up with a decent tasting bread by making it with lowfat buttermilk.  I use white cornmeal, add baking powder, an egg, some canola cooking oil, and one egg.  Mix enough batter to fill a good sized skillet half to the rim.  Some people don't like thick cornbread, but I do.  I also add a spoon of sugar to my cornbread mix.

There's no way to keep collard greens very low in calories and still have a good tasting dish (my opinion), but you can at least make it healthier.  Collards are about as good for you as any vegetable you can eat, so I don't worry about the extra calories all that much.