(1) Use the search option.
(2) IMHO, skipping is a much beter (and more effective) way to shave-off speed. However, a front brake is THE best way.
(3) The best place to learn skidding in a parking garage. Not all, but most, of them have rather slick ground surfaces that make skidding much easier. You can also try to learn it on grass, or after it rains.
(4) Ratios: go
here.