Bus from JR Beppu Station to the Hells

Hi
I have checked that there are buses from JR Beppu Station to the Hells in Kannawa District and Shibasaki District. Can I know how often are these buses and what is the cost.

Should I take the bus from Beppu Station directly to Shibasaki first or Kannawa. Which is more convenient.

I do not intend to visit all the 7 hells, which 3 would you recommend.

Thanks

Sandy

Many of your questions are answered here:
http://www.japan-guide.com/e/e4702.html

Can I know how often are these buses and what is the cost.

Frequent means every few minutes. The one way fare seems to be 320 yen.

Should I take the bus from Beppu Station directly to Shibasaki first or Kannawa. Which is more convenient.

Either way. There is no difference.

Thanks Uji.