Oita Kotsu Bus Fare - How to pay?

Hi! How much is typical bus fare for the Oita Kotsu bus line and how do you usually ride it and pay? I have no idea how we are to find the right bus and how we will know how much to pay and how to give payment to the driver.

We will be coming from Beppu going to Harmonyland. I've read that we should take the bus bound for Hiji station from the JR Kitsuki station but have no idea how to find the bus and how to ride it.

Many thanks!!

How to use local buses:
http://www.japan-guide.com/e/e2015.html

Bus stops are usually easy to find just outside of the train station. If in doubt, ask the station staff.

I guess I missed that part of this site. Very helpful, thank you for the information =D