Gray, I just went to the link you listed. It's technically correct but wildly misleading. This is not the way trumpet players approach the instrument. Everyone on this forum will back me up on that. That chart will only work in the niche situation of playing a Bb trumpet and reading C music. It this is the way you learn the instrument you will have to transpose while reading music that is actually written for the instrument. I doubt this is the situation you want to be in. Hope that helps.