Hi, Brenda -
Funny you should ask, because I was just thinking of giving it a try again myself.
I don't have a yogurt maker, which I understand is mostly a well-insulated container to hold the yogurt at the right temperature. Maybe they have different types - what does your catalog say?
Anyhow, I tried it once several years ago. I bought a container of plain yogurt with active cultures in it from the store. I followed a recipe I found in some "back to the land" type magazine, which used something like a couple of tablespoons of the storebought stuff and milk. Then I used a candy thermometer to reach the right temperature (whatver it was) and tried my best to keep the yogurt warm.
Didn't work very well - it turned out rather runny, but you could tell it was yogurt. It tasted okay, but not wonderful. I imagine that if you use a yogurt maker and are able to carefully maintain the right temperature, it would be just fine.
Good luck - let us know how it turns out!