go to www.davos.ch
there you will find all the info you need plus special deals on hotels and other stuff.
if you do stay there you will get a card that allows you to use the buses for free.
as for hiking...great place to be. for absolut beginners to advaced hikers. something for everybody.
great restaurants, nice city, super mountains, nice pool with spa, lake with beach pool. they also have a summer program where they offer free tours and other things every day.
klosters is a smaller town just down the mountain from davos. different flair. you have more options if you stay in davos.
as for hotels...that all depends how much you want to spend but the webside will help you find something that suits you.