If it's been fully cured (smoked, then hung for a few months), it likely just needs to be warmed through for serving (or even just sliced).
If it's soft, you might need to cook it, and then you could roast it in the oven ... a crock pot might be okay; it's hard to say without having seen it.
But if it's quite firm, I'd likely just slice pieces off like you might other dry cured hams like Prosciutto, speck, jamón or country ham.
If it's heavily salted, I'd be more likely to use it as a flavoring than a meat -- cut off bits, and add to vegetable dishes when cooking. It goes great with dark greens or in bean dishes. (I just had an excellent bean & ham soup last night at a meeting that a few of us treat as a pot-luck)
If it is a country ham, meaning salt-cured then you need to boil the salt out of it. I may get flamed for this, but that article is not how I process my ham. So here is what I do.
I get a lard tin, I usually have to cut off the hock to make the ham fit but since yours is split you may not have to. If it is not a salt cured ham, and is a city ham it may not be fit to eat if you do this, you could make ham soup maybe.
Anyway put the ham in the tin fill it full of water bring it up to a boil let it boil for about fifteen minutes then bring the heat down to medium-low for about 1/2 an hour then let it cool down enough so you can take it off the stove, but just barely cool enough. While it is cooling down get blankets and spread them out on the floor, one or two thin ones should do, then get some newspaper and spread that in the middle of the blankets put the tin in the middle of the newspaper and wrap the tin with the newspaper then wrap the blankets around it and then push it over into a corner overnight.
The next morning pull the ham out of the water give it a rinse and pat it dry, it will still be warm-to-hot. (I rotisserie ham hocks and small hams I get from my butcher but I have never done a full size ham I would imagine the amount of drippings would make a mess though.) Next I get my big roasting pan put the ham in it and pat it down with brown sugar, medium or dark is up to you. Then I cover it with aluminum foil, making sure I tent the foil so it doesn't touch the ham, and let it cook usually between four and five hours for a good size ham at about 325. The last half hour I take off the aluminum foil and if I feel it is necessary I add more brown sugar and let it caramelize.
I have been cooking ham this way for as long as I have been cooking and the process is passed down from my mother and her father before her. Farther back than that I cannot confirm or deny. :)
Here is a great article on country hams and other hams, just to make sure you do have a country ham, and gives other great suggestions on how to cook a ham, although they do it differently than I do.
http://www.amazingribs.com/recipes/porknography/zen_of_ham.html
Best Answer
Okay, there are a couple kinds of hams that you can deal with -
Dry cured - these hams are rubbed externally with a salt mixture, get covered with the salt mixture, which draws out much of the moisture, then are hung to further dry, and are smoked. These are also called "country" hams in the USA, and cured meats like Black Forest hams (Germany), jamon (Spain), prosciutto (Italy) all fall under this category, as well. Since they have such a low moisture content and a lot of the salt is in the meat, you would not receive this as frozen. These arrive in boxes, usually in some kind of a mesh or cloth bag, and can be kept at room temperature until you cook them. They do need to be scrubbed, skin and fat trimmed away, cooked in liquid to partially rehydrate, then cooked, thoroughly. These take a lot more time and effort to make, and their cost reflects that, but the flavor, because of less water content, is very intense. It is fantastic sliced thin after cooled/cold, as well.
Wikipedia - country hams
Most hams eaten in the USA, and ones that you generally buy at a grocery store, are water cured hams. The fact that it was frozen, the appearance, packaging and ingredients list all identify the ham you are asking about as a water cured ham. A saline/sugar/water solution is used to brine the ham.
While you can keep it in the fridge for a while, the brining method used here is more for flavor, not preservation, and those hams will go bad if you just leave them in the fridge for a long period of time.
Here is the USDA site with information about it, along with cooking times -
Ham that - USDA