I started eating liver a few months ago. I wouldn’t touch the stuff as a kid. I found that liver tastes excellent (yes, excellent!) when you a) season it and b) don’t overcook it.
If you are new to the idea of eating head-to-toe (eating the whole animal, not just the fancy parts) liver is a good organ to start with. Basically you will want to coat it in generous amounts of salt and pepper all over. Then I like to add either parsley or chives.
Place your desired fat in the frying pan (coconut oil, butter, olive oil etc.) and turn the heat to medium-low. I cook the liver by flipping it once and making sure each side is browned and the middle is slightly medium-rear. I find if you cook it too long the liver becomes tough.
Hopefully this helps you begin your head-to-toe eating adventure. I’ve only gone as far as liver and bone marrow. One of these days I’ll venture into heart and tongue.