Ham stock is made by putting the bone in a big pot, covering with water. Add - traditionally - onions, carrots and celery, salt and pepper and a bay leaf. Let simmer pretty much all day (six hours is pretty standard in stock recipes - with most people thinking it only gets better if you let it go ten or twelve). Remove the ham bone - most of the meat should fall off, but you may need to let it cool and cut the rest off. Then turn the meat and stock into soup.
Ham works particular good for bean soups - pretty much any beans or peas can be thrown into the pot. I like spinich. Potatos and cabbage are both good soup fillers. The thing with soup is that it really doesn't take a recipe - you throw in the vegetables that sound good to you, cook them up and serve them (though with peas or lentils if you want a good thick soup you need to get the proportions right - but thin pea soup still tastes fine). If you use dry beans (which are really cheap) you'll need to read the package so they cook. Same with fresh veggies - look in a cookbook so you don't get overcooked cabbage and raw potato to get a timing estimate. If you use canned beans and frozen vegetables your meal can be ready fifteen minutes after you get the stock done.
I have a great recipe that is white beans, spinich, a touch (like a tablespoon or two) of tomato paste, and some italian seasoning - maybe carrots and onions (can you tell I throw things into the pot as I go?).
Soups are a great time to experiment with cheap root vegetables. Turnips and rutabages get no respect, but are surprisingly tasty in soup.