Reading Porter's Handbook is a good start point, in conjunction with reading specific ports Makefile you want to work on to understand what it's doing.I would like to be able to use Rstduio and apache superset on BSD, but I've no idea how to port something or maintain it. I use both regularly so would be happy to have a go at doing them. What skills would I need and where would I get them from?
And maybe parts of Committer's Guide (especially Chapter 5 "Git Primer) would be helpful for non-committers like me.