How to add custom code from the bbHelp Club Answers

Many of the answers on this website include the custom code you need to use (and maybe modify) to achieve something related to bbPress. What is the best way to add this code?

Behind the scenes of bbHelp Club

The idea of the bbHelp Club website is to provide help with bbPress, and the website does use bbPress for community forums, while most of the other plugins (and theme) are developed by Dev4Press.

bbPress Help Club is now open

bbPress Help Club, or bbHelp Club for short(er) is now open, and everyone is welcome! If you are wondering what this club is, please, read on, if you like it, join us!