My mother fixed turnips like you would fix potatoes. We ate them raw if they were fresh, sometimes she would cook them and mash them, she even fried them or baked them like scalloped potatoes. She didn't care for turnip greens so we never had them.
My husband did not care for turnips so my kids have never had them. I used to buy turnips and would eat them raw - like people eat jicama. It does need to be fresh otherwise it is tough and bitter. Also they have gotten rather expensive here so haven't bought any in years.