Every year I plug the US Puzzle Championship, which this year happens on August 27th. What happens is I print out the puzzles, doodle on them with colored pencils, and type numbers and letters into an online form. It's fun! Register ahead of time, ie now.
You should also try all these fillomino puzzles. The puzzles are part of a different sort of competition where you're the judge. You vote on your four favorite puzzles, using any criterion. Vote for mine! (I'm not allowed to say which one it is.)