Games Workshop offers the core rules for its Age of Sigmar Rules free for the downloading.
What A Tanker 40K is a modification of Two Fat Lardies’ What A Tanker Game for the Warhammer 40K Universe
Man O War is a great game, but one thing I’ve always disliked about it are the fiddly cardboard ship templates that you use with markers to designate damage.
Universal Head has the solution: very nicely done ship cards that you can print out, slip into playing card protectors and mark with overhead pens.
It’s the perfect solution.
Boromir and Kermit have a tutorial on building a magnetic scoreboard for your Games Workshop BloodBowl games. Actually, there are a lot of sports games out there right now, and this would be adaptable to any of them.