Tonearm - 6:33 am on Oct 2, 2012 (gmt 0)

I have 3 employees currently and I've had about 5 others, but they all had to leave the company because they moved away. I've never had to fire anyone. A particular employee makes mistake after mistake, doesn't follow instructions well, and continuously stresses me out.

What is the best procedure to follow when considering firing an employee? Should I be issuing him warnings which he is required to sign?