Here are some of the things that I do when I have excess milk. (Ricotta and Crockpot Yogurt)
1) Heat a gallon of milk to 180 at about medium high in a large pan. (Rinsing the inside bottom of the pan in cold water before starting will help keep the milk from sticking to the bottom ;) You don't want to heat on high because you don't want this to come to a boil and scorch the milk.
2) Stir in 1/4 c. apple cider vinegar. You will begin to see the milk separate into curds (ricotta) and whey.
3) Use a slotted spoon to scoop the curds out into a strainer lined with cheesecloth or a thin hand-towel. This strainer should be sitting in a bowl so that the whey has some contained place to go ;)
4) Let the whey drain from the curds that you've scooped out. I do this by bringing the corners of my towel together, tying them with a rubber band, putting the rubber band around one of the kitchen cabinet handles, and letting it hang for ten minutes or so. There are a lot of ways to do it though; you'll have to find out what works best for you. (Some would gather the ends of the cloth together and tie securely with twine. Then, tie the bag to the handle of a large spoon and lay the spoon across the top oven rack with a bowl underneath. I just didn't want to leave my oven door open with four kids running around the house :P
As I understand it, this is not actually true ricotta as ricotta means "recooked". You can find "real" ricotta instructions with pictureshere.
For a wealth of information on various unique homemade things (including root beer, other cheeses, etc.), visit this page.
This professor also has a number of other cheese making instructions (complete with pictures).
I prefer this crockpot method for yogurt making.