How will I know when I will be finish with my height or growth spurt?
You'll be done with your growth when you stop growing -- I know it sounds redundant and too obvious, but the point is that once growth stops, it doesn't restart. Growth ramps up in stage 3 and then begins to slow down. When the rate drops below a rate of two inches per year, you'll have entered stage 4. From there it will continue to slow down until it reaches a full stop.
The questions in the Tanner Stage Calculator all deal with the secondary characteristics that appear during the stages. This gives a rough estimate of where you are in your development. When you get to stage 5, then you are pretty much done.