Reusing code for output in multiple labels

This is not for a class.

I have a timer form that counts down from any number perfectly. I was asked by my boss to make it multiple timers on one form.
When I made the code in the sub generic and passed in the values the timer needed (hour, min, timername) from a start button it seems not to matter which start button is pressed as the labels output the information for the last button pressed. I believe I need to multithread this, but am unsure how to do it.
Please let me know of your advice.
I have attached the code for the form in question

Also are there any good vb.net reference books? I have the MS one but feel need more reference books.

The attachment did not go through on first post. Trying again.