I found this HP tuning series on Youtube. This guy is really detailed, and tunes his own truck as he makes the videos. And the videos are within the last 3 or 4 months. It's not the 3800 engine, but you get the idea on where to start with tuning.

This one is about MAF tuning, but he has other videos to tune speed density, timing, torque, and PE. His first 2 volumes he explains the HP Tuner purpose, etc.
MAF Tuning and Scaling, Tuning Series Vol. 3, HP Tuners - YouTube