Paul it's not rocket science but if you have never done it then a bit of learning is in order for you init?
Here is a tube to watch
Here is a tube to watch
How To: Tapping Screw Threads - YouTube
There are many to choose from
It depends on the material you are taping into as to the requirements to make a thread.
In my sets I have one die of each size that can be adjusted to pinch a bit more material with every pass so I gauge the depth of thread by how much material I take out.
The taps are a set of three for each size comprising of a starter tap which tapers to get a bite on the material and forms the track of the thread.
The next is an intermediate tap which enlarges the track and starts to form the thread by taking material out.
The third is run up the track taking more material and forming the complete thread at full depth.
Done this way to keep the tools from overheating and or getting too tight at any point and breaking.
Lubrication helps to cool the material and tool and eases the action of threading
