I dunno if this helps you any but...90% of the package cars I drive have 6 gears Reverse-Low-1-2-3-4
Low is unnecessary unless your going up a hill or towing so don't worry about it, that would be the gear straight down from reverse. So 1 is to get you moving under 5mph, 2 is 5-15mph, 3 is 15-25, 4 is anything faster. If you want smooth shifts I suggest you start in 1st, go 2nd at 10mph, 3rd around 20 mph, and 4th once your past 25.
You will find that changing gears this way is really quick if your not in a loaded PC, but that's how the trucks are geared and you will be less jerky if you change gears quickly, most of the time I only use gear 1,3,4, (don't do that on a test obviously).
One more note, the older PC's like to grind and whine a bit when shifting, so best to delay your gear change 1 or 2 seconds after you depress the clutch.
Good luck