Use regular connect 4 rules unless playing some sort of variation. For complete rules go here for wikipedia's page on connect 4.
To simplify things, blue always goes first. Who gets which color is decided by piphi using a random number generator and choosing a number from 1 to 2. If it's 1 then the person who signed-up first is blue and if it's 2 then the second person to sign-up gets blue.
Games start as soon as enough people sign up and have been approved by piphi. People can be in a maximum of three connect 4 games at any time and there is currently no limit to the number of games in total (although a limit might be added later on if this gets big). There will be no need to keep a log of your game's moves since you can just check the game page's history.
There will be a time limit for each move! Each person get a maximum of 5 days to make their move, if a user takes longer than the time limit to make their move then the game is declared abandoned and none of the users get to be part of the Hall of Fame.
There is no undoing at all! Once you pressed "Save Changes" that's it, you can't go back.
If anyone has any ideas on how to improve this game, maybe make tournaments, or other games that are only possible on the AoPS Wiki, then please add them to the discussion page.