WBS Time Book with cost

Dear all,

i would like to know the steps to use time book with cost for a WBS, i never use this one and i saw in Forun some cases using KB21N but with out cost and other case Costing Sheet, to be honest i dont know which is the better process to have the Project team hours booked on the WBS

1 - How to setup a Tax per hour

2 - How to book time for WBS

3 -Which report we can use to get the time booked.

Thanks for support.

Marcelo Borini