Introduction to code base

Hi,
First off, apologies to MODS if this isnt the right place for this.

Im currently assessing the viability of using the arducopter code base for making an autopilot system for delivering a package ~300m in the air and returning to take off point, I want to modify the mission planner for this also to suit this also. Has to be dummy friendly.

Its a plan for a final year project, Im a computer science student so I have familiarity with programming.

So to the question, does anyone have any videos or extra resources in addition to those on the dev.ardupilot.com website? I cant seem to find much and Im struggling to wrap my head around it.

Thanks in advance!