What trip website do you find best?

Getting ready to fly the family to Cincinnati to visit one relative, and then St. Paul to visit another. I’ll need air and hotel. Was wondering, what website do you find best? Convenience, price, etc?

Also, know any good tourist destinations near either city that would be good for adults and a couple 10 year olds? Doesn’t have to be directly in either city, we’re willing to drive a bit if the attraction is interesting.