You've got a lot of options in terms of smoking a ham. For instance, you can brine, cure, or inject.
"Curing," means using nitrates and/or nitrites -- one effect is to turn the meat a familiar ham "pink." You can manipulate the texture, moisture and flavor profiles only very slightly using a cure, as opposed to a brine. Unless preservation is an issue, the primary reason to use cure with ham is for color.
"Brining," means a long soak in a salt-acid-sugar solution which may also contain herbs, spices and so on to advance the flavor profile. A brine differs from a generic marinade because of the salt. The salt and acid work together to create a more tender product, while the salt and sugar make it significantly moister.
Brining is a subject of some controversy when it comes to smoking large cuts of porks -- especially butts and picnics. Less so with ham, where it's more popular. When I cook butts I inject, but when I cook hams I brine. I find brining just works better with lean meats like ham, poultry and fish. If you're looking to create a specific and intense flavor profile you may want to consider injection; better though to let the ham speak for itself.
A typical salt/acid/sweet balance for a ham brine is 1 cup of (non iodized) table salt, 1 cup of sugar, and 1 cup of distilled vinegar. While maintaining similar concentrations I'd modify that brine considerably with fruit, wine, aromatics and other pork-friendly ingredients. We can discuss a brine which will compliment your ham and the other parts of your meal if you decide to go that way.
A seasoning rub or glaze, very light in salt, should also be used. Depending on how your ham is butchered, you may be able to remove the skin and rub beneath it, then retie the skin to the ham. I find this method works well, although it requires some butchering skill.
As a final note, you'll want to cook your ham to somewhere in the 165 - 185 internal temperature area. Trichinosis is simply not an issue in the US anymore, so ham is safe at the same temperatures as any other meat. You can eat it rare if you like. That said -- almost no one likes rare pork, and you'll absolutely freak anyone who prefers well done pork -- which is bound to be everyone else in your family. Furthermore, pork undergoes a major texture change at right around 160, where it firms up. But it also loses considerable moisture as temperatures increase above 140 or so. That's where brining pays off -- you can cook to a firm, tender, and moist texture and not scare the MIL.
IMO, ham for slicking is best smoked to 170 or even just a touch above, then tightly wrapped in cling wrap or foil, and rested for at least an hour (preferably longer) in a properly prepped insulated cooler.
Hope this helps you with some ideas,