My favorite RPG theme comics:

Order of the Stick: https://www.giantitp.com/comics/oots0001.html

Keep on the Borderlands: http://thekeepontheborderlands.thecomicseries.com/comics/fir...

Both are SFW.

Woah! Had no idea that PA is still around :) Two decades and still going strong!

My oldest son (10) also started with W40k - thanks to Warhammer Conquest.