It's not a difficult process at all. I thought that I'd need special equipment or lots of time, but it's easy to make your own yogurt, and a great way to cut down on paying for all the individual containers when you can just make your own.
I don't have a yogurt maker, and our oven doesn't have a pilot light, but you don't need that if you've got a crock pot. Start by putting your crock pot on the Stay Warm setting.
I make one 4 cup batch at a time. I take about 1/4 to 1/2 a cup of plain yogurt (starter) and set it aside, allowing it to warm up to room temperature. This yogurt can be from a batch you bought at the store or from the last batch you made. It must be plain yogurt, and none of that junk with no fat (i.e. full of artificial sweeteners).
I heat about 3 1/2 cups of milk in a Pyrex container in the microwave (you could do it on the stove if you wanted, but this is easier for me). Heat to about 170. That takes about 5 minutes for me in the microwave. If it's not there yet, then add 30 seconds at a time until it gets there. DON'T overheat to boiling. If there's a film, take it off. Try to avoid a film because then you've heated it a bit too much.
Keep the thermometer in the container and leave it in there, waiting for it to go down to about 105-110. Go do something else at this point, but don't forget about it.
You could put it all in the crock pot and put it in a container later, but I like to put it in the container it'll be in once it goes in the fridge. Get a quart jar (I just use a canning jar). Put some yogurt and warmed milk in it and swish it around. Then put all the milk and yogurt. Put a lid on it and put the jar in the crock pot. Turn off & unplug the crock pot but wrap a thick towel around the crock pot to keep in the warmth. Wait 4-8 hours (it's great to do this before bed and have it fresh in the morning) and then put your new yogurt in the fridge.
If you like yogurt Greek style, just put the yogurt on cheesecloth over a bowl and let the whey (slightly yellowed liquid) separate from the thicker part of the yogurt. If it's too thick, add some more whey in. Don't waste your whey. There's a lot of good stuff in there nutritionally. You can use that in place of water in recipes (though I haven't tried it in anything but bread). Sometimes I use the yogurt in place of water & milk in bread too. You could also drink it outright, but I don't know that I'd do that without some other flavoring (maybe in a smoothie or something).
If you're making a bunch of yogurt, you could use your whey to make ricotta. I haven't tried this, but, hey, ricotta is tasty.
You can flavor with jams, honey, fruit, whatever. I like mine with honey, but jam is always good too.