Here are few resources about the console commands or stuffs related to it within the game.
- A wide list of commands coming from quake 3 might be found on joz3d.net.
- The README file provides all added commands by the ioquake3 team.
- The lag remover code also has it own commands that you can read in Unlagged.txt.
- The VoIP feature has a bunch of commands in voip-readme.txt.
- Lastly, few other tips and tricks involving the console or just the configuration file of the games could be found on LAME's clanpage.