you havent given enough information to indicate you should be fearful of anything (as in villain raised or was tight), so I assume you are trying to maximize what you can get from villain. I like that this board is rainbow, so I'm not worried about a flush, but I also don't want to give villain any free cards to hit his straight, 2 pr or set. I bet 1/2 to 2/3 the pot. If he folds, he folds. If he calls, re-evaluate based on turn card.