Here are a couple of insanely easy ways to do turkey thighs in the crock pot.

My way:

Slice a medium onion thinly and place in bottom of slow cooker.

Skin the turkey thighs (my preference - I don't suppose you HAVE to remove the skin) and season to taste with salt/pepper. Place on top of onions. Pour in about 1/4 cup dry white wine. Dot tops of thighs with butter or margarine - 1 Tbsp or so should do. Cover and cook on high one hour, then on low another 3 hours (check with meat thermometer and aim for 165 degrees). Let stand 10-15 minutes before slicing. Use the broth to make gravy, or pour it into a sauce pan and boil it down to make a glaze.

A friend's way:

Simply put the thighs in the cooker with 1 cup apple juice
seasoned with 2 Tbsp soy sauce. That's it! Cook on low 4-5 hours.

Personally I prefer to start poultry on high for perhaps an
hour, then switch to low. There's something unappetizing to me about the idea of poultry sitting in a low temperature crock pot for the time it takes to get "up to speed." This occurred to me the first time I did some with butter pats on the top and noticed that it took at least an hour before the butter even started to melt!